Time  Speaker  Title  Resources  

09:00 to 09:45  Marjolein Dijkrsta  Predicting and designing the selfassembly of colloidal particles: a computer game  
09:45 to 10:30  Jose Maria Tavares 
Phase diagrams of self assembly patchy particles Patchy particles are hard cores decorated with dis crete attractive sites (patches) on their surfaces and are used as models for systems with strongly anisotropic interactions. The bonding of particles through their patches promotes the formation of large selfassembled aggregates. The interaction between two patches is specified by an energetic parameter and by the volume available for the bond (bonding volume), that sets the loss of (translational) entropy when a bond is formed [1]. Numerical simulations and theoretical calculations of the phase diagram of onecomponent patchy parti cle fluids have revealed that lowering the number of patches (or valence M) depresses the critical proper ties (critical temperature, critical density, and criti cal pressure). Because the twophase region shrinks, the density of the coexisting liquid also decreases with M, opening up the possibility of low density equilib rium liquid states (empty liquids) that nevertheless have a percolated structure (network fluids). This effect is limited by the lowest possible value of the valence for which both percolation and phase sepa ration can be found, M = 3 [2]. To overcome this limitation, we have proposed and studied two families of patchy particle models, that are expected to show an effective valence M < 3: (i) a single component system with particles that have 2 patches of type A and n patches of type B that form AA and AB bonds only (2AnB model) [3, 4] and (ii) binary mixtures, where each specie has a different number of patches and similar or dissimilar patches [5]. In this talk, I will present some of the striking results obtained for the liquid vapour phase diagrams of these models us ing Wertheim’s theory (in most cases confirmed by Monte Carlo simulations) [1]. The phase diagram of the 2AnB model exhibits a reentrant liquid binodal (see Fig. 1), that leads to the appearance of equilibrium liquid states of arbi trarily low densities [3, 6]. It can be shown that this reentrance is originated by the competition between two types of entropic defects that perturb the ground state. In some extreme cases, when the entropy of AB bonds is much larger than that of AA [4] or when rings of AA bonds are present [7], a closed liquid vapor coexistence region with an upper and a lower critical point is obtained. The phase diagrams of binary mixtures of patchy par ticles with different valences (M1 and M2) and a single energy scale (i.e., all patches identical) have a strong dependence on M1 and M2, originated by the compe tition between the entropy of bonding and the entropy of mixing. The calculation of the critical properties of these mixtures reveals that the empty fluid regime is only obtained for (M1, M2) = (2, 3) and that, for gen eral mixtures, the role of the entropy of mixing in de termining the critical properties can only be neglected when M2 − M1 = 1 [5]. Corresponding author: jmtavares@fc.ul.pt


10:30 to 10:55    Coffee Break  
10:55 to 11:40  G. V. Pavan Kumar 
PlasmonActivated Colloidal Assembly : Chains and Networks Light activated, assembly, movement and pattern for mation of softmatter has been studied in the context of micro and nanorobots in fluidic environments. These processes have also gained interest in the con text of lightactivated dynamic networks that can be controlled in space and time, which further serves as interesting experimental models to study driven ac tive matter and emergence phenomena. To this end, a variety of surface optical effects have been explored that can effectively interface softmatter with confined optical fields. One such optical process is excitation of surface plas mon polaritons (SPPs). Interaction of visible light with thinfilms and nanostructures made of coinage metals, such as gold and silver, can be used to excite SPPs at metaldielectric interface. These surface elec tromagnetic waves not only confine electric fields at subwavelength scale, but also facilitate thermal field gradients due to ohmic heating. In an essence, SPPs provide optical and thermal fields at metalfluid in terface, which can be controlled by an external laser beam. We have been interested in interaction of softmatter with SPPs at metalfluid interface [1, 2]. Specifically, we have been interested in questions such as: how colloidal meso and nanostructures behave in thermo optical fields of SPPs? How will their assembly and dynamics alter when the dimensions of metal struc ture change? What kind of unconventional patterns emerge due to interaction of SPPs with complex flu ids? In this presentation, we will introduce some relevant optothermal effects of SPPs and discuss how they can be harnessed to study assembly, dynamics and pattern formation of softmatter at metalfluid interface. Par ticularly, we will discuss about formation of colloidal chains and networks in multiple plasmofluidic fields. We will conclude by discussing some new prospects of nanowire plasmons [3] that can confine and move colloids in a quasione dimensional channel. This work was partially funded by DST Nanomission, India and AFRL, USA Corresponding author: pavan@iiserpune.ac.in


11:40 to 12:25  Prerna Sharma 
Self assembly of cyclic polygon shaped fluid membranes through pinning 2D liquid monolayer membranes of aligned rod like particles form in presence of depletion attraction in duced by nonadsorbing polymer coils [1]. Surface ten sion drives these monolayers to be circular in shape with edge fluctuations controlled by the chirality of the constituent rods [2]. Surprisingly, we find that fluid membranes assembled form mixtures of long and short rods are cyclic polygonal in shape with short rods forming the outer lobes and longer rods forming the inner faceted core of the polygon. We show that the origin of this anisotropic shape of membranes lies in the phenomenon of how one liquid spreads over an other in presence of pinning sites. We outline the necessary and sufficient constraints on the nature of rods to obtain the stable out of equilibrium cyclic poly gon membranes. Our results show the unique counter intuitive scenario where disorder lead to self assembly of ordered structures. We would like to acknowledge IISc, ISROSTC and SERBDST for funding this work. Corresponding author: prerna@iisc.ac.in


12:25 to 12:45  Sujata Tarafdar 
Hierarchical selfassembly of desiccation crack patterns in clay induced by a uniform electric field Crack patterns formed by desiccation in clay are known to give rise to characteristic patterns [1, 2]. The patterns are affected by various factors, such as the drying material, the substrate and ambient condi tions like temperature and relative humidity. External conditions like electric fields and magnetic fields also control details of the crack patterns. Cylindrically symmetric static DC (i.e. Direct Cur rent) electric fields [3] and AC (Alternating Current) fields [4] can be used to tailor the crack patterns in specific geometrical arrangements. Here we describe another experiment. We applied a uniform static electric field to an aque ous layer of clay suspension while drying. This caused a selfassembly of the cracks into an interesting pat tern, dictated by the energy supplied to the system. Initially closely spaced straight cracks appear at the positive electrode. As the sample dries these cracks merge together in small groups. Several stages of this merging produces the final hierarchical pattern. The final pattern is distinctly treelike, or river like, consisting of hierarchical structures as shown in Fig. 1. River like crack structures have been observed and discussed previously [5], but not in dried clay pastes as we observe here. We try to analyse the patterns and explain their origin. The redistribution of mobile ions in the aqueous clay slurry is assumed to be responsible for the pattern formation. The process may be useful in producing tailored crack patterns for applications in nanopatterning. We sincerely thank Tajkera Khatun and Sudeshna Sir car for participating in this work and for offering valu able suggestions. Corresponding author: sujata.tarafdar@gmail.com


12:45 to 14:15    Lunch  
14:15 to 15:00  W. Benjamin Rogers 
Using entropy to program selfassembly of DNAcoated colloids DNA is not just the stuff of our genetic code; it is also a means to build new materials [1]. For instance, grafting DNA onto small particles can, in principle, ‘program’ the particles with information that tells them exactly how to put themselves together—they ‘selfassemble.’ Recent advances in our understand ing of how this information is compiled into specific interparticle forces have enabled the assembly of in teresting crystal phases [2], and could be extended to the assembly of prescribed, nonperiodic structures [3]. However, structure is just one piece of the puzzle; in actuality, selfassembly describes a transition between a disordered state and an ordered state, or a pathway on a phase diagram. In this talk, I will present experiments showing that the information stored in DNA sequences can be used to design the entire assembly pathway. Using free DNA strands that either induce or compete with bind ing between particles, I will show that it is possible to create suspensions with new types of phase behav ior [4], enabled by our control of the entropy of the free strands [5]. I will also discuss preliminary ex periments showing that we can measure directly the dynamics of transitions between different phases, us ing a combination of techniques from dropletbased microfluidics, video microscopy, and image analysis. Going forward, this work could prove especially use ful in nanomaterials research, where a central goal is to manufacture functional materials by growing them directly from solution. We would like to acknowledge support from the Na tional Science Foundation (NSF DMR1710112). Corresponding author: wrogers@brandeis.edu.edu


15:00 to 15:20  Debasish Chaudhuri 
Confinement and crowding sets morphology and position of bacterial chromosome To explain experimental results showing shape, size and dynamics of E.coli chromosomes in growing cells, we consider a polymer model consisting of a circular backbone to which sideloops are attached, confined to a cylindrical cell [1, 2]. Such a model chromosome spon taneously adopts a helical shape, which is further com pacted by molecular crowders to occupy a nucleoidlike subvolume (Fig. 1). With increasing cell length, the longitudinal size of the chromosome increases in a non linear fashion to finally saturate, its morphology gradu ally opening up while displaying an increasing number of helical turns. For shorter cells and low crowder densi ties, the chromosome extension varies nonmonotonically with cell size, which we show is associated with a ra dial to longitudinal spatial reorganization of the crow ders. Confinement and crowders constrain chain dynam ics leading to anomalous diffusion. While the scaling ex ponent for the mean squared displacement of centre of mass grows and saturates with cell length, that of indi vidual loci displays broad distribution with a welldefined maximum. Despite several experimental efforts, in E.coli bacteria, the mechanism for chromosome segregation re mains elusive. We propose chromosomal segregation via interchromosome repulsion mediated by protein produc tion. The simulation results show good agreement with experiments. Corresponding author: debc@iopb.res.in


15:20 to 15:40  Sayantan Majumdar 
Memory Retention in disordered biopolymer networks Adaptive materials can change their mechanical prop erties depending on external cues in a controlled manner. In this talk, I will describe a novel type of mechanical adaptation in crosslinked networks of Factin, a ubiqui tous protein found in the cytoskeleton of eukaryotic cells. We show that shear stress changes the nonlinear mechan ical response of the network even long after that stress is removed [1]. The duration, magnitude and direction of forcing history all change this mechanical response. While such memory is longlived, it can be erased simply by force application in the opposite direction. We also show that the observed mechanical adaptation is consis tent with stressdependent changes in the nematic order of the constituent filaments. This demonstrates that F actin networks can exhibit analog readwrite mechanical memory. In disordered condensed matter systems, memory ef fects originate from out of equilibrium nature of the materials involving slow nonexponential relaxation pro cesses. Such effects have been observed in systems as diverse as, charge density wave conductors [2], molecular glasses [3], crumpled candy wrappers [4], superconduc tors [5], granular and amorphous materials [6–8]. In the last part of my talk, I shall also briefly discuss about our preliminary data on nonmonotonic stressrelaxation dy namics in collagen networks (Fig. 1) in the light of other memory encoding condensed matter systems mentioned above. I would like to thank M.L. Gardel (U. Chicago), A.J. Levine (UCLA), L.C. Foucard (UCLA) for the part of work on actin networks. I thank M.K. Firoz (RRI), S.R. Nagel (U. Chicago) and D. Hexner (U. Chicago) for the ongoing work on memory dynamics in collagen networks. I acknowledge SERB (DST) for support through a Ra manujan Fellowship. Corresponding author: smajumdar@rri.res.in


15:40 to 16:00    Coffee Break  
16:00 to 17:00  Daan Frenkel 
From selfassembly to cell recognition (InfosysICTS Chandrasekhar  Lecture 2) A holy grail of nanotechnology is to create truly complex, multicomponent structures by selfassembly. Most selfassembly has focused on the creation of "structural complexity". In my talk, I will discuss "Addressable Complexity": the creation of structures that contain hundreds or thousands of distinct building blocks that all have to find their place in a 3D structure. Experiments have demonstrated the feasibility of making such structures. Simulation and theory yield surprising insights that can inform the design of novel structures and materials. Surprisingly, the design principles for addressable selfassembly may provide a tool to distinguish different cell surfaces. 

17:00 to 18:30    Poster Session  
19:00 to 22:00    Workshop Dinner 
Time  Speaker  Title  Resources  

09:00 to 09:45  Alexei Tkachenko 
Onset of natural selection and "reversal of the Second Law" In population of autocatalytic heteropolymers The second law of thermodynamics states that the entropy of a closed system increases with time. Life represents a remarkable example of the opposite trend in an open, nonequilibrium system. Indeed, both informational and thermodynamic entropies decrease in the course of biological evolution reflecting everincreasing complexity of living organisms and their communities \cite{schroedinger}. Conceptually, the problem of the origin of life can be viewed as a search for the simplest physical system capable of such spontaneous reduction of entropy and growth of complexity \cite{anderson}. Selfreplicating systems based on informationcoding polymers are of crucial importance in biology. We have carried out a general theoretical and numerical analysis of the problem of spontaneous emergence of autocatalysis for heteropolymers capable of templateassisted ligation driven by cyclic changes in the environment \cite{JCP}. One of our key results is the existence of the first order transition between the regime dominated by free monomers and that with a selfsustaining population of sufficiently long chains. We provide a simple, mathematically tractable model supported by numerical simulations, which predicts the distribution of chain lengths and the onset of autocatalysis in terms of the overall monomer concentration and two fundamental rate constants. The templateassisted ligation allows for heritable transmission of the information encoded in chain sequences thus opening up the possibility of longterm memory and evolvability in such systems. In order to explore this scenario, we focus at a reduced version of our original model \cite{arxiv}, by assuming that a template of just two ‘letters’ long is sufficient to catalyze a ligation of two chain ends. Within this reduced model, we can study both numerically and analytically the evolution of the sequence pool of such autocatalytic heteropolymers made of Z types of monomers (‘letters’). Remarkably we find that the sequence entropy, initially at its maximum (consistent with the Random Sequence Approximation used in \cite{JCP}), gets slowly reduced to a much lower value. A closer analysis shows that out of... Our model, while not detailing specific chemical realization, describes a generic mechanism of formation of long autocatalytic heteropolymers. Furthermore, we show that this system is inherently unstable with respect to symmetry breaking in the sequence space. This leads to reduction of sequence entropy, signaling a spontaneous increase in the information. This can be interpreted as an onset of Darwinian behavior, and may explain future emergence of the natural selection. The sequence information entropy in a pool of autocatalitic heteropolymers (black lines), and the natural logarithm of the number of surviving twoletter words, 2mers (red lines) plotted vs. time in 5 different realizations of our system. b)c) The heatmap visualizing concentrations of 2mers at the early (b) and late (c) stages of the system’s evolution. Acknowledgements This research used resources of the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility, at Brookhaven National Laboratory under Contract No. DESC0012704.


09:45 to 10:30  James Swan 
OutofEquilibrium SelfAssembly of Mutually Polarizable Nanoparticle Suspensions in Toggled External Fields Structured materials selfassembled from dispersions of nanoparticles and colloids have numerous demonstrated applications including wave guides for optical computing, microlens arrays for energy harvesting, and porous electrodes for energy storage. As the particles selfassemble under a steady driving force, a thermodynamic constraint on the phase separation kinetics forces a tradeoff between quality of the selfassembled microstructure and its rate of formation. This is a key difficulty preventing adoption of selfassembled nanoparticle materials at scale. Dynamically selfassembling dispersions with interactions that vary in time do not have this constraint and offer a promising method to suppress kinetic arrest while accelerating growth of ordered nanostructures. For dispersions of polarizable dielectric or paramagnetic nanoparticles, varying the particle interactions in time is easily achieved by toggling the external electric or magnetic field on and off cyclically in time. Because of the cyclic driving force, materials formed by toggled selfassembly are dissipative and outofequilibrium, and therefore are classified as active matter, along with particles that swim, grow, or selfrotate. As toggled selfassembly cannot be understood in terms of equilibrium thermodynamics, new theories must be developed before it can be used to reliably fabricate nanomaterials. I have developed a computational and theoretical model for dispersions of mutually polarizable nanoparticles in steady or toggled external fields. The model takes into account polarization from both the external field and from disturbance fields generated by induced dipoles on surrounding particles. Using Brownian dynamics simulations, I show that cyclically toggling the external field can avoid kinetic barriers and yield large, wellordered crystalline domains in these dispersions. The rate of phase separation, local and global quality of the selfassembled structures, and range of tunable parameters leading to acceptable selfassembly are all enhanced with toggled fields compared to steady fields. Toggling can also stabilize new phases that are never observed in steady fields, such as fluidfluid coexistence or bodycenteredorthorhombic crystal. The growth mechanism and terminal structure of the dispersion are easily controlled by parameters of the toggling protocol, allowing for selection of processes that yield rapidly selfassembled, low defect structures. Although structures formed via toggled selfassembly are inherently outofequilibrium, I show that they can be understood in terms of equations of state valid for steady fields. I perform thermodynamic calculations that predict the outofequilibrium terminal states in terms of the parameters of the toggling protocol. 

10:30 to 10:55    Coffee break  
10:55 to 11:40  Suri Vaikuntanathan  Dissipation induced transitions in soft matter systems  
11:40 to 12:25  M. Scott Shell 
Systematic multiscale models and physics using the relative entropy Many molecular processes involve ranges of length and time scales that cannot be tackled with atomicscale simulations. Instead, coarsegrained molecular models are necessary to interrogate such systems from a theoretical point of view. We discuss a fundamental approach to the identification of such models and more generally of emergent physical behavior from manybody systems. We proposed that a quantity called the relative entropy measures the information lost upon coarse graining and is the natural thermodynamic metric for such tasks [1,2]; its minimization provides a universal variational principle for coarsegraining [3,4]. In particular, this broad statisticalmechanical framework can improve simulation models of complex biomolecular and liquidstate systems, and uncover important driving forces and degrees of freedom [4–6]. We discuss conceptual and numerical aspects of this approach and illustrate its use in several case studies, including our recent efforts to improve models of hydrophobic interactions and complex mixtures using meanfield, multibody interaction potentials inspired by embedded atom models of metallic systems [7,8]. Corresponding author: michael.gruenwald@utah.edu


12:25 to 12:45  Sarika Bhattacharya  Glassforming ability of a binary mixture: The role of entropy  
12:45 to 14:15    Lunch  
14:15 to 15:00  Prabal Maiti  Twophase thermodynamic(2PT) model for efficient entropy calculation in liquid state  
15:00 to 15:20  Apratim Chatterjee  Role of special crosslinks in the organization of DNApolymer at micron length scales  
15:20 to 15:40  Anand Srivastava 
Lipids degeneracy in the (sub100nm) membrane organization: Thermodynamics costs behind maintaining complex lipid diversity The rich structural complexity of biological mem branes arises from the chemical diversity of its constituents. Di↵erential inter and intramolecular interactions result in preferential segregation and clustering of certain types of lipids and proteins, giving rise to a variety of lateral organization on the membrane surface. Recently, Edward Ly man’s group at Delaware carried out multiple long timescales allatom molecular dynamics simulations (tens of microseconds long) with carefully chosen lipid compositions to reproduce a variety of phases [1, 2]. We focus on the systems that exhibit liquid ordered and liquiddisordered (Lo/Ld) coexistence. The three systems with their fractional composi tions are (i) PSM/POPC/Chol (0.47/0.32/0.21) (ii) PSM/DOPC/Chol (0.43/0.38/0.19) (iii) DPPC/DOPC/Chol (0.37/0.36/0.27). We analyze these trajectories and numerically calcu late the degree of nonaffineness of individual lipids in their local neighborhood and their topological re arrangements [3]. We use these data to distinguish between the Lo and Ld regions in the membrane sys tem at molecular length scales [4]. The three chosen systems exhibit di↵erent molecular level substructures and unique Lo/Ld interface boundaries. We also explore the molecularorigin of this variety in organization using tools from simple statistical mechanics theories. And try to quantify the thermodynamics cost of arriving at a given mem brane substructure using a di↵erent lipid types and compositions. The authors thank Edward Lyman (University of Delaware, USA) for sharing the AA simulation trajec tories, which was generously made available by D.E. Shaw Research. AS would also like to thank the IISc Bangalore for the startup grant and the DST, India for the Early Career Award. Corresponding author: anand@iisc.ac.in


15:40 to 16:00    Coffee break  
16:00 to 17:00  Daan Frenkel 
Entropy production and phoretic transport (InfosysICTS Chandrasekhar  Lecture 3) It sounds so innocent: `Heat never spontaneously flows from cold to hot’, but almost nothing in this statement is as simple as it seems. In my talk, I will consider the microscopic mechanism by which thermal gradients cause flow along liquid/solid interfaces. In particular, I will discuss the problems in formulating a correct microscopic description of such `phoretic’ transport processes. Phoretic transport becomes increasingly relevant, as experiments probe transport in nanoscale channels. It turns out that our microscopic understanding of flows driven by thermodynamic, rather than mechanical, forces is far from complete. 
Time  Speaker  Title  Resources  

09:00 to 09:45  Guruswamy Kumaraswamy 
Why are ice templated particle polymer hybrids flexible? Macroscopic objects formed from particle assemblies are typically brittle, precluding their use in several ap plications. We have demonstrated that icetemplating an aqueous dispersion of rigid colloidal particles and polymer, and crosslinking this polymer in the frozen state results in the formation of remarkably flexible colloidal assemblies[1]. Centimeterscale monoliths prepared in this manner recover elastically after com pression to 10% of their original size. This is remark able when we consider that the monoliths are predom inantly inorganic, with a particle weight fraction of 90%. Monoliths prepared in this manner are soft, with moduli in the range of tens of kPa. The Poisson ratio for monolith deformation can be calculated based on the change in sample dimensions during compression, and from the ratio of shear and Young’s moduli. The methods are consistent, and yield values close to zero. The scaling of moduli with density suggests the me chanical response of the monolith in the linear regime is governed by thickening of the pore walls, rather than wall bending. For higher strains, there is a dra matic increase in stress corresponding to buckling of pore walls. The moduli of the monoliths increase linearly with temperature, indicating that the mechanical response is entropic in origin. We have demonstrated that flex ible elastic hybrid monoliths can be prepared using different particles, different polymers and even dif ferent crosslinking chemistries. Therefore, the me chanical response appears to be a function largely of the microstructure developed by the preparation pro cess viz. ice templating, followed by crosslinking in the frozen state. We demonstrate that this protocol results in the formation of a unique microstructure: polymers crosslinked in the frozen state form a mesh around particles in the pore walls[2, 3]. Subtle differences in the protocol for assembling nanoparticles play a critical role in determining their properties. Macroporous monoliths that are chemi cally identical but that are prepared using small vari ations in the ice templating protocol exhibit quali tatively different mechanical behaviour, ranging from flexible elastic monoliths to plastic monoliths that fail at low compressive strains. We employ a variety of experimental techniques to characterize the structure and dynamics in these monoliths. We demonstrate that the preparation protocol modulates the spatial variation in crosslink density. Elastic scaffolds have a uniform distribution of crosslinks while scaffolds that have the same average crosslink density but spatially heterogeneous crosslinks exhibit brittle failure[2, 3]. Finally, I show that we can use the same ice tem plating protocol to form flexible linear chainlike as semblies that represent a convenient model system to study polymer physics. I will present results on the dynamics of active colloidal chains prepared using this protocol[4]. We would like to acknowledge SERBChemical En gineering PAC, BRNS and IUSSTF for funding. KS, SC and BB acknowledge funding from CSIR and DST Inspire. Corresponding author: g.kumaraswamy@ncl.res.in


09:45 to 10:30  Michael Gruenwald 
Ligand effects in the selfassembly of nanocrystals into superlattices We present a computational study of ligand effects in the selfassembly of nonspherical nanocrystals [1]. We focus on the two particle shapes most often found in experiments (cuboctahedral or truncated octahe dral) and determine their assembly behavior as a function of ligand length and solvent quality. Our model, which is based on a coarsegrained description of ligands and a schematic representation of solvent effects, reproduces many of the experimentally ob served superstructures [2–6], including superlattices with partial and shortranged orientational alignment of nanocrystals [5, 6]. Our simulations show that small differences in nanoparticle size and shape, ligand cov erage, and solvent conditions, can lead to markedly different selfassembled superstructures due to subtle changes in the free energetics of ligand interactions. These results help explain the large number of differ ent reported superlattices selfassembled from seem ingly similar particles and can serve as a guide for the selfassembly of specific superstructures. We would like to acknowledge IISc, ISROSTC and SERBDST for funding this work. ∗ Corresponding author: michael.gruenwald@utah.edu


10:30 to 10:55    Coffee break  
10:55 to 11:40  R. Rajesh 
Entropy driven phase transitions in hardcore lattice gas models One of the simplest systems to show phase transitions is a collection of particles that interact only through excluded volume interactions. Well known examples include hard sphere gas which undergoes a liquidsolid freezing transition and long rods which undergo an isotropicnematic transition, or nearest neighbour ex clusion models on lattices, also known as hard core lattice gas models. In such systems, all allowed con figurations have equal energy and hence temperature plays no role, and phases transitions, if any, are driven by gain in entropy. Simulations of such systems suffer from issues of equi libration at high densities, especially when the ex cluded volumes are large, due to long lived metastable states. This has resulted in not many accurate re sults being known for hard core lattice gas models in three dimensions, or for two dimensional systems close to full packing. In this talk, I will elaborate upon a grand canonical Monte Carlo algorithm that implements cluster moves in an efficient manner which is able to equilibrate such systems even at the fully packed density. By implementing this algorithm, I will discuss recent results that have been obtained for sys tems of differently shaped particles like rods, squares, cubes, plates, etc. [1, 2]. Corresponding author: rrajesh@imsc.res.in


11:40 to 12:25  Ning Xu 
Phase behaviors of softcore particles at high densities Softcore particles interacting via Springlike repul sion exhibit multiple reentrant crystallizations with various solid structures. In this talk, we will present our recent observations of the novel twodimensional melting scenario due to the reentrance and surprising finding of quasicrystals. According to the KTHNY theory [1–4], the melting of a twodimensional solid is a twostage process. There exists an intermediate phase called hexatic phase be tween solid and liquid. Transitions from solid to hex atic and from hexatic to liquid are both continuous. Recently, it has been reported that the hexaticliquid transition of hard particles is discontinuous [5] and the transition can evolve from discontinuous to continuous when the softness of particles is tuned [6]. For soft core particle systems which reach the first maximum melting temperature T m at a crossover density ρ m , we find that ρ m acts as a transition point. Hexaticliquid transition at ρ < ρ m exhibits strong first order tran sition features. There is a density interval in which liquid and hexatic phases coexist. The interval de creases with increasing temperature and tends to van ish at T m . When ρ > ρ m , however, the hexaticliquid transition becomes continuous. Therefore, in softcore systems with reentrant crystallization, density should affect the nature of the hexaticliquid transition [7]. At much higher densities after several reentrance, we surprisingly observe the existence of twodimensional quasicrystals [8]. Up to now, quasicrystals have been found in multicomponent systems such as al loys [9] and in monocomponent systems with mul tiple length scales in particle interactions [10–15] or with anisotropic particles such as tetrahedral and patchy particles [16, 17]. In all these systems, multiple length scales are present in particle size, interaction, or anisotropy, which seem to be the consensual condi tion for quasicrystals to occur. The quasicrystals that we found are unexpectedly formed by monodisperse, isotropic particles interacting via the simple softcore potential without multiple length scales. We find not only dodecagonal but also octagonal quasicrystals, which have not been found yet in soft quasicrystals. In our quasicrystals, particles tend to form pentagons. A pentagon surrounded by an nfold polygon constructs the complex structural unit to develop the nfold qua sicrystalline order. In liquid states prior to the liquid solid transition, we already observe some signs of the development of the quasicrystalline order, including the accumulation of pentagons and the emergence of two competing length scales. We have also verified that our quasicrystals are stable by showing that their formation is independent of history and they have the lowest inherent structure potential energy, compared with other crystalline states. Corresponding author: ningxu@ustc.edu.cn


12:25 to 12:45  Tapati Dutta 
Growth kinetics of NaCl crystals in a drying drop of gelatin: transition from faceted to dendritic growth The study of droplets of complex fluids, dried through evaporation, reviewed recently by Sefiane [1, 2] is becoming a rapidly growing field of research. The widespread interest is due to the basic physics aspect as well as promising applications in technology [3], quality control and medical diagnostics [4]. A drying droplet may exhibit a host of features, concentric ring patterns [5, 6], cracks[7, 8], and other interesting mor phologies. A fact well known since many years is that gels provide a good medium for the growth of crystals [9]. We report a study on the kinetics of drying of a droplet of aqueous gelatin containing sodium chloride. The process of drying recorded as a video clearly shows different regimes of growth leading to a variety of crystalline patterns. Large faceted crystals of mm size form in the early stages of evaporation Fig. 1(a), followed by highly branched multi fractal patterns with micron sized features Fig. 1(b). We simulate the growth using a simple algorithm incorporating aggregation and evaporation, which reproduces the cross over between the two growth regimes Fig. 1(c  d). As evaporation proceeds, voids form in the gel film. The time development of the fluidvoid system can be characterized by the Euler number. A minimum in the Euler number marks the transition between the two regimes of growth Fig. 2 . We sincerely thank Abhra Giri for participating in this work. Corresponding author: sujata.tarafdar@gmail.com tapati dutta@sxc.com, tapati mithu@yahoo.com


12:45 to 14:15    Lunch  
14:15 to 15:00  Shashi Thutupalli 
Towards controlled assembly in active matter We describe our efforts towards constructing synthetic active particle systems capable of tunable assemblies and organised structures. Active particles, including swimming microorganisms, autophoretic colloids and droplets, are known to selforganize into ordered struc tures at fluidsolid boundaries. The entrainment of particles in the attractive parts of their spontaneous flows has been postulated as a possible mechanism underlying this phenomenon. Here, combining exper iments, theory and numerical simulations, we demon strate the validity of this flowinduced ordering mech anism in a suspension of active emulsion droplets. We show that the mechanism can be controlled, with a variety of resultant ordered structures, by simply al tering hydrodynamic boundary conditions. Thus, for flow in HeleShaw cells, metastable lines or stable traveling bands can be obtained by varying the cell height. Similarly, for flow bounded by a plane, dynamic crystallites are formed. At a noslip wall the crystallites are characterised by a continuous out ofplane flux of particles that circulate and reenter at the crystallite edges, thereby stabilising them. At an interface where the tangential stress vanishes the crystallites are strictly twodimensional, with no out ofplane flux. We rationalize these experimental re sults by calculating, in each case, the slow viscous flow produced by the droplets and the dissipative, long ranged, manybody active forces and torques between them. The results of numerical simulations of motion under the action of the active forces and torques are in excellent agreement with experiments. Our work [1] elucidates the mechanism of flowinduced phase sepa ration (FIPS) in active fluids, particularly active col loidal suspensions, and demonstrates its control by boundaries, suggesting new routes to geometric and topological phenomena in active matter. Corresponding author: Shashi Thutupalli  shashi@ncbs.res.in


15:00 to 15:45  Ran Ni 
“Entropic Effects” in Active Hard Spheres Over the past decade, active hard spheres have be come a benchmarking model system for studying the nonequilibrium physics in active matter. Although active hard spheres are intrisically out of equilibrium, we still find some equilibrium entropylike effects in the system to drive the phase transition and self organization in the system. In particular, I will talk about our recent work on active depletion forces [1], entropy driven activepassive demixing [2], and the formation of strongly hyperuniform fluids in systems of active hard spheres [3]. Corresponding author: r.ni@ntu.edu.sg


15:45 to 16:05  Habib Rahbari  Characterizing rare fluctuations in soft particulate flows  
16:05 to 16:30    Closing  
16:30 to 17:00    Coffee break 
Time  Speaker  Title  Resources  

11:00 to 12:30  Rama Govindarajan 
Droplet and vortex interactions in the context of clouds In this talk I will discuss the dynamics of droplets in the vicinity of vortices. The dynamics is described by simple parameterfree equation which have a boundary layer structure. Droplets within a critical distance from the vortex centre can participate in caustics events, and seed rapid droplet growth by collisions and coalescence. Our simulations provide evidence for this in three dimensions. I will then discuss how small droplets falling under gravity are affected by the Basset history force, a force which is normally extremely cumbersome to compute, but which we solve by an efficient method. Finally I will discuss how turbulence is affected by condensation on droplets. I will discuss some of these in the context of clouds. 
Time  Speaker  Title  Resources  

11:00 to 12:30  Atsushi Ikeda 
Viscosity divergence and dynamical slowing down at the jamming transition Jamming transition of athermal particles is characterized by the divergence of the viscosity. This transition looks very similar to the glass transition, but there are several key differences. One of the differences is that the dynamical slowing down is apparently absent in the jamming transition. In this talk, I will report our recent study on the dynamics near the jamming transition. We especially focus on the dynamics in the simplest setting. i.e. relaxation from the random configuration of soft particles without shear. I show that the relaxation exhibits remarkable slowing down. I also show that this relaxation is dominated by a non trivial anomalous mode and is quantitatively related to the viscosity divergence. 
Time  Speaker  Title  Resources  

09:30 to 11:00  Chandan Dasgupta 
Statistical mechanics of systems of interacting classical particles (Lecture 1) Lecture 1: Mayer cluster expansion for nonideal gas, correlation and response functions 

11:00 to 11:30    Coffee  
11:30 to 13:00  Sanat Kumar 
The Role of Chain Conformational Entropy on SelfAssembly of Surfactants, Polymers and Nanoparticles (Lecture 1) “Selfassembly (SA) in the classic sense can be defined as the spontaneous and reversible organization of molecular units into ordered structures by noncovalent interactions. The first property of a selfassembled system that this definition suggests is the spontaneity of the selfassembly process: the interactions responsible for the formation of the selfassembled system act on a strictly local level—in other words, the nanostructurebuilds itself. “  WIkipedia This lecture will first focus on the basics of selfassembly and will show that this process only occurs for special systems. The ideas of Israelachvili on the critical micelle concentration and the packing parameter will be introduced. This lecture then naturally leads to delineating the conformational entropy of the surfactant tail, which is driven by ideas of entropic elasticity first espoused by Flory and deGennes. The application of these ideas to block copolymer selfassembly, to polymer crystallization and nanoparticle selfassembly will be explored in lecture 3. Texts: Israelachvili, Intermolecular and Surface Forces, Academic Press, 1992 Rubinstein, Colby Polymer Physics, Oxford, 2003 Lecture 1 (Israleachvili, Chapters 16,17)


13:00 to 14:30    Lunch  
14:30 to 16:00  Dov Levine 
Order, Entropy, Information, and Compression (Lecture 1) In my lectures, I will begin with an idiosyncratic discussion of the idea of organization, ordering, and order. I will then introduce some relevant ideas from information theory, including Shannon entropy, Kolmogorov complexity, and elementary concepts from coding theory, followed by to a discussion of data compression and its relation to Shannon entropy. This will lead to a resume of results from ongoing research into the identification and quantification of order in systems far from equilibrium. 

15:30 to 16:00    Coffee  
16:30 to 17:30    Tutorial 
Time  Speaker  Title  Resources  

09:30 to 11:00  Chandan Dasgupta 
Statistical mechanics of systems of interacting classical particles (Lecture 2) Lecture 2: Elements of liquidstate theory, introduction to classical density functional theory 

11:00 to 11:30    Coffee  
11:30 to 13:00  Sanat Kumar 
The Role of Chain Conformational Entropy on SelfAssembly of Surfactants, Polymers and Nanoparticles (Lecture 2) Lecture 2 (Rubinstein & Colby, Chapters 2, 3, 5)


13:00 to 14:30    Lunch  
14:30 to 16:00  Dov Levine 
Order, Entropy, Information, and Compression (Lecture 2) In my lectures, I will begin with an idiosyncratic discussion of the idea of organization, ordering, and order. I will then introduce some relevant ideas from information theory, including Shannon entropy, Kolmogorov complexity, and elementary concepts from coding theory, followed by to a discussion of data compression and its relation to Shannon entropy. This will lead to a resume of results from ongoing research into the identification and quantification of order in systems far from equilibrium. 

15:30 to 16:00    Coffee  
16:30 to 17:30    Tutorial 
Time  Speaker  Title  Resources  

09:30 to 11:00  Sanat Kumar 
The Role of Chain Conformational Entropy on SelfAssembly of Surfactants, Polymers and Nanoparticles (Lecture 3) Lecture 3 (Various sources)


11:00 to 11:30    Coffee  
11:30 to 13:00  Bulbul Chakraborty 
Statistical Mechanics of Athermal Systems: Edwards Ensemble, Entropy and Friction (Lecture 1) Lecture 1: Introduction to Edwards’ ideas, Microcanonical and Canonical Ensembles, Concept of Compactivity and Angoricity.


13:00 to 14:30    Lunch  
14:30 to 16:00  Sriram Ramaswamy 
Dynamics, Entropy Production & Defects in Active Matter (Lecture 1) I will begin with a general Langevin framework for active matter dynamics [1] in which the “active terms” are directly linked to a driving force most naturally interpreted as a chemical potential imbalance between fuel and reaction products. I will consider the entropy production properties of specific instances of such equations of motion for individual active particles as well as for active field theories [2, 3]. I will also discuss the defectunbinding transition of active nematic systems [4], which has a natural energyentropy aspect. I acknowledge support from the Tata Education and Development Trust and from a J C Bose Fellowship of the Science & Engineering Research Board. Corresponding author: sriram@iisc.ac.in


15:30 to 16:00    Coffee  
16:30 to 17:30    Tutorial 
Time  Speaker  Title  Resources  

09:30 to 11:00  Bulbul Chakraborty 
Statistical Mechanics of Athermal Systems: Edwards Ensemble, Entropy and Friction (Lecture 2) Lecture 2: The dual networks of jammed packings: Contact network and Force Tilings 

11:00 to 11:30    Coffee  
11:30 to 13:00  Dov Levine 
Order, Entropy, Information, and Compression (Lecture 3) In my lectures, I will begin with an idiosyncratic discussion of the idea of organization, ordering, and order. I will then introduce some relevant ideas from information theory, including Shannon entropy, Kolmogorov complexity, and elementary concepts from coding theory, followed by to a discussion of data compression and its relation to Shannon entropy. This will lead to a resume of results from ongoing research into the identification and quantification of order in systems far from equilibrium. 

13:00 to 14:30    Lunch  
14:30 to 16:00  Sriram Ramaswamy 
Dynamics, Entropy Production & Defects in Active Matter (Lecture 2) I will begin with a general Langevin framework for active matter dynamics [1] in which the “active terms” are directly linked to a driving force most naturally interpreted as a chemical potential imbalance between fuel and reaction products. I will consider the entropy production properties of specific instances of such equations of motion for individual active particles as well as for active field theories [2, 3]. I will also discuss the defectunbinding transition of active nematic systems [4], which has a natural energyentropy aspect. I acknowledge support from the Tata Education and Development Trust and from a J C Bose Fellowship of the Science & Engineering Research Board. Corresponding author: sriram@iisc.ac.in


15:30 to 16:00    Coffee 
Time  Speaker  Title  Resources  

09:30 to 11:00  Bulbul Chakraborty  Statistical Mechanics of Athermal Systems: Edwards Ensemble, Entropy and Friction (Lecture 3)  
11:00 to 11:30    Coffee  
11:30 to 13:00  Sriram Ramaswamy 
Dynamics, Entropy Production & Defects in Active Matter (Lecture 3) I will begin with a general Langevin framework for active matter dynamics [1] in which the “active terms” are directly linked to a driving force most naturally interpreted as a chemical potential imbalance between fuel and reaction products. I will consider the entropy production properties of specific instances of such equations of motion for individual active particles as well as for active field theories [2, 3]. I will also discuss the defectunbinding transition of active nematic systems [4], which has a natural energyentropy aspect. I acknowledge support from the Tata Education and Development Trust and from a J C Bose Fellowship of the Science & Engineering Research Board. Corresponding author: sriram@iisc.ac.in


13:00 to 14:30    Lunch  
14:30 to 15:15  Guiseppe Foffi 
Beyond isotropic models for dynamically arrested colloids, introducing directionality In this talk I will briefly review the dynamic phase diagram of colloidal particle interacting with a shortranged attractive interactions. This realistic model posses a number of exotic properties such as a reentrant melting, two different kid of glass, an arrested phase separation resulting in a gel structure. Most of this unusual phenomenology has been now confirmed in experiments and computer simulations. The above scenario, is restricted to isotropic colloid, however in recent years a lot of interest has been devoted to the effect of directional attractive forces due to the progress in particles synthesis. I will present some recent results on the effect of directionality on the dynamics of these systems in connection, in particular, with the idea of locally favoured structure of a glass former. 

15:15 to 16:00  Hideyuki Mizuno 
Vibrational properties in the continuum limit of amorphous solids The thermal properties of crystalline solids follow universal laws that are explained in terms of phonons. Amorphous solids are also characterized by universal laws that are, however, anomalous with respect to their crystalline counterparts. These anomalies begin to emerge at very low temperatures, suggesting that the vibrational properties of amorphous solids differ from phonons at very low frequencies, even in the continuum limit. In this talk, I will show that phonons coexist with soft localized modes in the continuum limit. I will also show that the phonons follow the Debye law, whereas the soft localized modes follow another universal nonDebye law. Finally I will discuss about origin of the soft localized modes. 

15:30 to 16:00    Coffee  
16:30 to 17:30    Tutorial 
Time  Speaker  Title  Resources  

09:30 to 11:00  Srikanth Sastry 
Phenomenology of glass forming liquids and glasses  Lecture 1 An overview will be presented of the phenomenolog y of glass forming liquids, glasses, and the glass transition, as a prelude to more extended expositions of specific themes that will be explored in the subsequent lectures in the school. The topics covered will include the nature and characterization of the dynamics, and dynamical slow down in glass forming liquids, the role of configurational entropy in descriptions of such dynamical slow down, heterogeneous dynamics, growing length scales in glass formers, and a mention of related topics concerning yielding of glasses and jamming. 

11:00 to 11:30    Coffee  
11:30 to 13:00  Jorge Kurchan 
Entropy in the evolution of almost integrable systems Almost integrable systems are ubiquitous: weakly nonlinear waves, planetary systems, globular clusters, the FremiPastaUlam problem, many well studied Quantm chains... The approach to equilibrium is slow, because it is done precisely through the integrability breaking. On the other hand, they offer us an opportu nity of understanding the precise role played by Entropy at each stage, because the evolution is, in a sense, reversible.


13:00 to 14:30    Lunch  
14:30 to 16:00  Srikanth Sastry 
Phenomenology of glass forming liquids and glasses (Lecture 2) An overview will be presented of the phenomenology of glass forming liquids, glasses, and the glass transition, as a prelude to more extended expositions of specific themes that will be explored in the subsequent lectures in the school. The topics covered will include the nature and characterization of the dynamics, and dynamical slow down in glass forming liquids, the role of configurational entropy in descriptions of such dynamical slow down, heterogeneous dynamics, growing length scales in glass formers, and a mention of related topics concerning yielding of glasses and jamming. 

15:30 to 16:00    Coffee  
16:30 to 17:30    Tutorial 
Time  Speaker  Title  Resources  

09:30 to 11:00  Francesco Sciortino 
Entropy in SelfAssembly (Lecture 1) I will discuss the role of entropy in some of the most relevant selfassembly processes. The outline of the lectures is the following: Introduction
Corresponding author: francesco.sciortino@uniroma1.it


11:00 to 11:30    Coffee  
11:30 to 13:00  Francesco Zamponi 
Mean field theory of the glass transition (Lecture 1) The development of a mean field theory of glasses started in the 80s, through the work of Kirkpatrick, Thirumalai and Wolynes. They identified a class of mean field spin glass models, whose qualitative behav ior is very similar to the one of supercooled liquid and glasses measured in the laboratory. They proposed that these spin glass models could serve as represen tative of a broad universality class, called the Ran dom First Order Transition (RFOT) class, in which the glass transition would fall, at least at the mean field level. To substantiate this claim, they proposed that a system of ddimensional interacting particles would fall in this class in the d → ∞ limit [1]. During the subsequent two decades, a lot of work has been done on RFOT spin glass models, which provided many important predictions on the thermodynamics and dynamics of RFOT systems: glass transition, aging, effective temperatures, complexity, dynamical heterogeneities... However, proving that the original conjecture of [1] is correct took another decade, and the program was completed in the last few years. In these lectures I will review the solution of parti cle systems in d → ∞. I will show that the behavior is precisely the one of the RFOT universality class. I will start by the study of the equilibrium dynamics and show the existence of a dynamical glass transition similar to the one of ModeCoupling Theory [2]. Next, I will show how the long time limit of the dynamics in the glass phase can be studied via the replica method using the “state following” or FranzParisi construc tion [3]. Finally, I will briefly discuss the Gardner and jamming transitions [4]. During the lectures, physical concepts such as the dy namical glass transition, the complexity, the Kauz mann transition, the outofequilibrium glass state, and the criticality of jamming will be discussed. Methodologically, we will introduce dynamical and replica techniques. The lectures are based on a book which is currently being written [5]. Corresponding author: www.phys.ens.fr/∼zamponi


13:00 to 14:30    Lunch  
14:30 to 16:00  Ludovic Berthier 
Measuring the configurational entropy in computer simulations of deeply supercooled liquids (Lecture 1) In these lectures, I will employ the material presented in the introductory lectures, in particular the basics of liquid state theory and statistical mechanics to explain how the configurational entropy of supercooled liquids can be measured in computer simulations of supercooled liquids [1]. I will first explain why we must care about the configurational entropy, how it is defined and what are the conceptual problems associated to this important quantity, from the illdefined concept of thermodynamic metastability to issues related to polydisperse liquid models. I will then talk about computer simulations of super cooled liquids, how they are done, and what can be hoped to be achieved using this important tool. In particular, I will emphasize the new opportunities offered by the recent development of the SWAP algorithm [2] to explore more ambitiously than before the thermodynamic properties of deeply supercooled liquids [3]. Then I will show how in practice one defines and mea sures using computer simulations various proxies for the configurational entropy, from the potential energy landscape approach, from the FrenkelLadd thermodynamic construction, from the FranzParisi free energy, and from the pointtoset correlation length measurement. These lectures have strong connections with the mean field results presented in the parallel lectures by F. Zamponi and J. Kurchan. Corresponding author: ludovic.berthier@umontpellier.fr


15:30 to 16:00    Coffee  
16:30 to 17:30    Tutorial 
Time  Speaker  Title  Resources  

09:30 to 11:00  Francesco Zamponi 
Mean field theory of the glass transition (Lecture 2) The development of a mean field theory of glasses started in the 80s, through the work of Kirkpatrick, Thirumalai and Wolynes. They identified a class of mean field spin glass models, whose qualitative behav ior is very similar to the one of supercooled liquid and glasses measured in the laboratory. They proposed that these spin glass models could serve as represen tative of a broad universality class, called the Ran dom First Order Transition (RFOT) class, in which the glass transition would fall, at least at the mean field level. To substantiate this claim, they proposed that a system of ddimensional interacting particles would fall in this class in the d → ∞ limit [1]. During the subsequent two decades, a lot of work has been done on RFOT spin glass models, which provided many important predictions on the thermodynamics and dynamics of RFOT systems: glass transition, aging, effective temperatures, complexity, dynamical heterogeneities... However, proving that the original conjecture of [1] is correct took another decade, and the program was completed in the last few years. In these lectures I will review the solution of parti cle systems in d → ∞. I will show that the behavior is precisely the one of the RFOT universality class. I will start by the study of the equilibrium dynamics and show the existence of a dynamical glass transition similar to the one of ModeCoupling Theory [2]. Next, I will show how the long time limit of the dynamics in the glass phase can be studied via the replica method using the “state following” or FranzParisi construc tion [3]. Finally, I will briefly discuss the Gardner and jamming transitions [4]. During the lectures, physical concepts such as the dy namical glass transition, the complexity, the Kauz mann transition, the outofequilibrium glass state, and the criticality of jamming will be discussed. Methodologically, we will introduce dynamical and replica techniques. The lectures are based on a book which is currently being written [5]. Corresponding author: www.phys.ens.fr/∼zamponi


11:00 to 11:30    Coffee  
11:30 to 13:00  Francesco Sciortino 
Entropy in SelfAssembly (Lecture 2) I will discuss the role of entropy in some of the most relevant selfassembly processes. The outline of the lectures is the following: Introduction
Corresponding author: francesco.sciortino@uniroma1.it


13:00 to 14:30    Lunch  
14:30 to 16:00  Patrick Charbonneau 
Bridging between meanfield and real glasses (Lecture 1) Recent years have seen remarkable advances in the meanfield theory of glasses. But do these theoretical predictions actually explain the behavior of real physi cal systems? In these lectures, we will study this ques tion using numerical and theoretical tools that allow to systematically interpolate between one limit [1] and the other. By tuning spatial dimension or the inter action range between particles, we can indeed identify theoretically robust features and physical phenomena that fall beyond the meanfield scenario. In these lectures, I will build on the material presented in previous and parallel lectures, especially the basics of liquid state theory and the meanfield theory of glasses. While L. Berthier’s lectures will mostly fo cus on the properties of glassy states, mine will center on the dynamical slowdown of an (metastable) equi librium liquid. More specifically, I will explore the following topics.
I thank warmly all my collaborators in this extended scientific effort. The last couple of years of this re search program were supported by a grant from the Simons Foundation (No. 454937). Corresponding author: https://chem.duke.edu/labs/charbonneau


16:00 to 18:00  Susan Coppersmith 
From bits to qubits: a quantum leap for computers (ICTS Distinguished Lecture) The steady increase in computational power of information processors over the past halfcentury has led to smart phones and the internet, changing commerce and our social lives. Up to now, the primary way that computational power has increased is that the electronic components have been made smaller and smaller, but within the next decade feature sizes are expected to reach the fundamental limits imposed by the size of atoms. However, it is possible that further huge increases in computational power could be achieved by building quantum computers, which exploit in new ways of the laws of quantum mechanics that govern the physical world. This talk will discuss the challenges involved in building a largescale quantum computer as well as progress that we have made in developing a quantum computer using silicon quantum dots, some of which is enabled by concepts developed in the context of statistical physics and nonlinear dynamics. Prospects for further development will also be discussed. 
Time  Speaker  Title  Resources  

09:30 to 11:00  Francesco Zamponi 
Mean field theory of the glass transition (Lecture 3) The development of a mean field theory of glasses started in the 80s, through the work of Kirkpatrick, Thirumalai and Wolynes. They identified a class of mean field spin glass models, whose qualitative behav ior is very similar to the one of supercooled liquid and glasses measured in the laboratory. They proposed that these spin glass models could serve as represen tative of a broad universality class, called the Ran dom First Order Transition (RFOT) class, in which the glass transition would fall, at least at the mean field level. To substantiate this claim, they proposed that a system of ddimensional interacting particles would fall in this class in the d → ∞ limit [1]. During the subsequent two decades, a lot of work has been done on RFOT spin glass models, which provided many important predictions on the thermodynamics and dynamics of RFOT systems: glass transition, aging, effective temperatures, complexity, dynamical heterogeneities... However, proving that the original conjecture of [1] is correct took another decade, and the program was completed in the last few years. In these lectures I will review the solution of parti cle systems in d → ∞. I will show that the behavior is precisely the one of the RFOT universality class. I will start by the study of the equilibrium dynamics and show the existence of a dynamical glass transition similar to the one of ModeCoupling Theory [2]. Next, I will show how the long time limit of the dynamics in the glass phase can be studied via the replica method using the “state following” or FranzParisi construc tion [3]. Finally, I will briefly discuss the Gardner and jamming transitions [4]. During the lectures, physical concepts such as the dy namical glass transition, the complexity, the Kauz mann transition, the outofequilibrium glass state, and the criticality of jamming will be discussed. Methodologically, we will introduce dynamical and replica techniques. The lectures are based on a book which is currently being written [5]. Corresponding author: www.phys.ens.fr/∼zamponi


11:00 to 11:30    Coffee  
11:30 to 13:00  Ludovic Berthier 
Measuring the configurational entropy in computer simulations of deeply supercooled liquids (Lecture 2) In these lectures, I will employ the material presented in the introductory lectures, in particular the basics of liquid state theory and statistical mechanics to explain how the configurational entropy of supercooled liquids can be measured in computer simulations of supercooled liquids [1]. I will first explain why we must care about the configurational entropy, how it is defined and what are the conceptual problems associated to this important quantity, from the illdefined concept of thermodynamic metastability to issues related to polydisperse liquid models. I will then talk about computer simulations of super cooled liquids, how they are done, and what can be hoped to be achieved using this important tool. In particular, I will emphasize the new opportunities offered by the recent development of the SWAP algorithm [2] to explore more ambitiously than before the thermodynamic properties of deeply supercooled liquids [3]. Then I will show how in practice one defines and mea sures using computer simulations various proxies for the configurational entropy, from the potential energy landscape approach, from the FrenkelLadd thermodynamic construction, from the FranzParisi free energy, and from the pointtoset correlation length measurement. These lectures have strong connections with the mean field results presented in the parallel lectures by F. Zamponi and J. Kurchan. Corresponding author: ludovic.berthier@umontpellier.fr L. Berthier and G. Biroli, Theoretical perspective on the glass transition and amorphous materials, Rev. Mod. Phys. 83, 587 (2011). 

13:00 to 14:30    Lunch  
14:30 to 16:00  Patrick Charbonneau 
Bridging between meanfield and real glasses (Lecture 2) Recent years have seen remarkable advances in the meanfield theory of glasses. But do these theoretical predictions actually explain the behavior of real physi cal systems? In these lectures, we will study this ques tion using numerical and theoretical tools that allow to systematically interpolate between one limit [1] and the other. By tuning spatial dimension or the inter action range between particles, we can indeed identify theoretically robust features and physical phenomena that fall beyond the meanfield scenario. In these lectures, I will build on the material presented in previous and parallel lectures, especially the basics of liquid state theory and the meanfield theory of glasses. While L. Berthier’s lectures will mostly fo cus on the properties of glassy states, mine will center on the dynamical slowdown of an (metastable) equi librium liquid. More specifically, I will explore the following topics.
I thank warmly all my collaborators in this extended scientific effort. The last couple of years of this re search program were supported by a grant from the Simons Foundation (No. 454937). Corresponding author: https://chem.duke.edu/labs/charbonneau


15:30 to 16:00    Coffee  
16:30 to 17:30    Tutorial 
Time  Speaker  Title  Resources  

09:30 to 11:00  Ludovic Berthier 
Measuring the configurational entropy in computer simulations of deeply supercooled liquids (Lecture 3) In these lectures, I will employ the material presented in the introductory lectures, in particular the basics of liquid state theory and statistical mechanics to explain how the configurational entropy of supercooled liquids can be measured in computer simulations of supercooled liquids [1]. I will first explain why we must care about the configurational entropy, how it is defined and what are the conceptual problems associated to this important quantity, from the illdefined concept of thermodynamic metastability to issues related to polydisperse liquid models. I will then talk about computer simulations of super cooled liquids, how they are done, and what can be hoped to be achieved using this important tool. In particular, I will emphasize the new opportunities offered by the recent development of the SWAP algorithm [2] to explore more ambitiously than before the thermodynamic properties of deeply supercooled liquids [3]. Then I will show how in practice one defines and mea sures using computer simulations various proxies for the configurational entropy, from the potential energy landscape approach, from the FrenkelLadd thermodynamic construction, from the FranzParisi free energy, and from the pointtoset correlation length measurement. These lectures have strong connections with the mean field results presented in the parallel lectures by F. Zamponi and J. Kurchan. Corresponding author: ludovic.berthier@umontpellier.fr L. Berthier and G. Biroli, Theoretical perspective on the glass transition and amorphous materials, Rev. Mod. Phys. 83, 587 (2011). 

11:00 to 11:30    Coffee  
11:30 to 13:00  Patrick Charbonneau 
Bridging between meanfield and real glasses (Lecture 3) Recent years have seen remarkable advances in the meanfield theory of glasses. But do these theoretical predictions actually explain the behavior of real physi cal systems? In these lectures, we will study this ques tion using numerical and theoretical tools that allow to systematically interpolate between one limit [1] and the other. By tuning spatial dimension or the inter action range between particles, we can indeed identify theoretically robust features and physical phenomena that fall beyond the meanfield scenario. In these lectures, I will build on the material presented in previous and parallel lectures, especially the basics of liquid state theory and the meanfield theory of glasses. While L. Berthier’s lectures will mostly fo cus on the properties of glassy states, mine will center on the dynamical slowdown of an (metastable) equi librium liquid. More specifically, I will explore the following topics.
I thank warmly all my collaborators in this extended scientific effort. The last couple of years of this re search program were supported by a grant from the Simons Foundation (No. 454937). Corresponding author: https://chem.duke.edu/labs/charbonneau


13:00 to 14:30    Lunch  
14:30 to 16:00  Francesco Sciortino 
Entropy in SelfAssembly (Lecture 3) I will discuss the role of entropy in some of the most relevant selfassembly processes. The outline of the lectures is the following: Introduction
Corresponding author: francesco.sciortino@uniroma1.it


15:30 to 16:00    Coffee  
16:30 to 17:30    Tutorial 
Time  Speaker  Title  Resources  

09:30 to 11:00  Magdaleno MedinaNoyola 
Nonequilibrium Kinetics of the Transformation of Liquids into Physical Gels J. M. OlaisGovea, L. LopezFlores, and M. MedinaNoyola A major stumbling block for statistical physics and materials science has been the lack of a universal principle that allows us to understand and predict elementary structural, morphological, and dynamical properties of nonequilibrium amorphous states of matter. The recentlydeveloped nonequilibrium selfconsistent generalized Langevin equation (NESCGLE) theory, however, has been shown to provide a fundamental tool for the understanding of the most essential features of the transformation of liquids into amorphous solids, such as their aging kinetics or their dependence on the protocol of fabrication. In this work we focus on the predicted kinetics of one of the main fingerprints of the formation of gels by arrested spinodal decomposition of suddenly and deeply quenched simple liquids, namely, the arrest of structural parameters associated with the morphological evolution from the initially uniform fluid, to the dynamically arrested spongelike amorphous material. The comparison o f the theoretical predictions with simulation and experimental data measured on similar but more complex materials, suggests the universality of the predicted scenario. 

11:00 to 11:30    Coffee  
11:30 to 13:00  Remi Monasson 
Phase transitions in highdimensional statistical inference (Lecture 1) Lecture 1: HighDimensional Inference: Basic techniques
References:


13:00 to 14:30    Lunch  
14:30 to 15:30  Amit Ghosal 
Glassy behavior associated with melting of twodimensional Coulomb clusters We present responses of a small number of Coulombinteracting particles in twodimensional confinements, across the crossover from their solid to liquidlike behaviors. Here, irregular confinements emulate the role of disorder. Focusing first on the thermal melting, where zeropoint motion of the particles are frozen, we explore the signatures of a 'hexaticglass' like behavior. While static correlations, which investigate the translational and bond orientational order [1,2], indicate a hexaticlike phase at low temperatures, dynamical correlations show considerably slow relaxations. Using density correlations we probe intriguing inhomogeneities arising from the interplay of the irregularity in the confinement and longrange interactions. The relaxation at multiple time scales show stretchedexponential decay of spatial correlations for Coulombparticles in irregular traps [1,3]. Temperature dependence of characteristic time scales, depicting the structural relaxation of the system, show strong similarities with those observed for the glassy systems. Our results indicate that some of the key features of supercooled liquids emerge in confined systems. more so with irregular confinements. The analysis of normal modes [4] elucidates how long time behavior of the system is encoded in the quasilocalized modes. Time permitting, we extend our discussions to include the effects of quantum fluctuations. Our results, using quantum Monte Carlo techniques for Boltzmann particles, seem to indicate complementary mechanism for the quantum and thermal crossovers in Wigner molecules [5]. We will also discuss our recent analyses upon including the effects of quantum statistics.


15:30 to 16:00    Coffee  
16:30 to 17:30    Tutorial 
Time  Speaker  Title  Resources  

09:30 to 11:00  Remi Monasson 
Phase transitions in highdimensional statistical inference (Lecture 2) HighDimensional Inference: Unsupervised Learning with Neural Networks


11:00 to 11:30    Coffee  
11:30 to 13:00  Mahesh M Bandi 
Applying Higherorder Turbulence Spectra from Energy to UAV Kolmogorov’s 1941 theory elucidating the spectrum of turbulent velocity fluctuations forms the cornerstone of contemporary turbulence research. This result requires one to measure the velocity everywhere within the turbulent flow at the same time instant. However, many situations exist where measurements are needed over time at one or few fixed spatial (Eulerian) locations, sometimes involving not velocity but its higher powers. The physical interpretation of such measurements strongly diverges from the Kolmogorov framework. In this talk, I will review the revised theoretical framework and support it with evidence from our experiments in two and three dimensional flows. I will then explain how this revised framework provides a toolkit to address a diverse range of questions in Energy, UAV mechanics, Environmental Sciences, and perhaps even Life Sciences. 

13:00 to 14:30    Lunch  
14:30 to 16:00  Remi Monasson 
Phase transitions in highdimensional statistical inference (Lecture 3) HighDimension Inference: Application to protein modeling
References:


15:30 to 16:00    Coffee  
16:30 to 17:30  Remi Monasson  Phase transitions in highdimensional statistical inference (Lecture 4) 
Time  Speaker  Title  Resources  

10:30 to 11:00    Coffee  
11:00 to 12:00  Stephan Herminghaus 
Artificial microswimmers: individual and collective phenomena Plankton provides the most important route of injection of solar energy into the biosystem. It is therefore of major importance to attain a deep understanding of swimming motility and swarming of these microorganisms. As their natural habitats include turbulent (oceanic photosphere) and still (lacustrine) waters as well as the benthic (seafloor) areas, a wide variety of geometries and flow conditions are to be studied. We discuss a number of phenomena found recently in both natural singlecell swimmers (Chlamydomonas reinhartii) and artificial liquid microswimmers consisting of selfpropelling 'oil' droplets. Some emphasis is given to properties which may be relevant for biofilm formation, such as adhesion and swarm formation, in particular in nontrivial geometries. 

13:00 to 14:30    Lunch 
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10:30 to 11:00    Coffee  
11:00 to 12:00  Vijay Kumar Krishnamurthy 
Interacting active particles: singlefile diffusion and fluctuationinduced forces ActiveBrownianparticles (ABPs) and runandtumble particles (RTPs) are minimal realizations of scalar active matter. We will start by discussing exact solutions for noninteracting RTPs in 1D in both unconfined and confined geometries. We will then move on to discuss singlefilediffusion in a system of interacting RTPs in 1D and show that the MSD of a tagged particle displays scaling behavior with the density and activity with an asymptotic t^{1/2} dependence on time. This is true also for ABPs confined in a narrow annular channel. We will then present our preliminary experimental results on interacting ABPs, realized as isotropic selfpropelled disks on a vibrated granular shaker, and demonstrate that various statistical quantities compare favourably with simulations. Finally, we will discuss fluctuationinduced interactions between anisotropic inclusions in a nonequilibrium heatbath composed of interacting ABPs. 

13:00 to 14:30    Lunch 
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11:10 to 12:30  Samriddhi Sankar Ray 
Turbulent Transport: Beyond Spherical Particles We present recent results on nonspherical particles and elastic fibers in a turbulent flow. In particular, we discuss the issue of preferential sampling of flows by such "particles" with internal degrees of freedom and compare them with the more standard spherical particle approach. If time permits, we will present recent results on the emergence of collective motion for active rods and disks in fully developed turbulence. 
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11:10 to 12:30  Muhittin Mungan 
AQSautomata, state transition graphs, returnpoint memory and random maps AQSautomata arise naturally in the description of the athermal dynamics of a disordered system  such as spin glasses  when a slowly changing uniform driving force is applied. The response of such systems is characterized by abrupt transitions between quasistatic configurations which are generally irreversible, giving thus rise to hysteresis. The dynamical response of such systems can be described in terms of a pair of random, directed and acyclic graphs, capturing the transitions triggered by force increases and decreases, respectively. Properties such as returnpoint memory emerge then as features of these graphs. In this talk I will develop the graphtheoretic description of AQSautomata and then present recent work with T. Witten on modelling the AQS dynamics by random maps. 
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11:10 to 12:30  Kapilanjan Krishnan 
The Physics of Beauty – A hairy story The perception of beauty is strongly linked to order and symmetry. These perceptions engraved into our evolutionary psychology as we survive by being the fittest. However, quantifying these perceptions, and the technical truth underlying them has many challenges, some of which will be shared in the context of hair. Two specific problems are (1) the dynamics of the tangling/detangling of hair, and (2) the movement of hair. Getting stronger analytical insights on the impact of microscale material parameters against macroscopic variations in the amount of structural disorder or momentum distributions would help design products for consumers. 
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11:10 to 12:30  Rituparno Mandal 
Extreme Active Matter at High Densities Extreme active matter, comprising selfpropelled particles characterised by large persistence time \tau_p and high Péclet number, exhibits remarkable behaviour at high densities. As \tau_p → 0, the material undergoes a conventional fluidtoglass transition via density relaxation, as one reduces the active propulsion force f . In the other limit, \tau_p → ∞, the fluid jams at a critical point on lowering f to f^∗ (∞), with stresses concentrated along forcechains. In between these limits, the approach to dynamical arrest at low f , goes through a phase characterised by intermittency in the kinetic and potential energy. This intermittency is a consequence of long periods of jamming followed by bursts of plastic yielding associated with Eshelby deformations, akin to the response of dense amorphous solids to an externally imposed shear. In the vicinity of the intermittencyfluid phase boundary, correlated plastic events result in large scale vorticity and turbulence. Dense extreme active matter brings together the physics of glass, jamming, plasticity and turbulence, in a new state of driven classical matter. 
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11:10 to 12:30    Discussions 
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15:00 to 16:00  Surajit Sengupta 
Solid rigidity: A thermodynamic origin story School textbooks tell us that the main difference between a solid and a liquid is the ability of the former to retain its shape. Any attempt at changing the shape of a solid is resisted by an internal elastic stress unless the deformation crosses a limiting value; at which point the solid fails. This naive viewpoint, although of great practical value, is, however, fundamentally incorrect. For example, one can argue that given enough time, atoms in the solid can always rearrange to eliminate stress no matter how much, or how little, the solid is deformed. Resolution of this paradoxical result lies at the core of our understanding of the behavior of solids under deformation. Adapting ideas which were introduced recently to study glasses, we find that rigidity arises a result of a hidden firstorder phase transition between phases which differ in the way they respond to changes of shape [1]. When deformed by any amount, howsoever small, the rigid solid goes into a metastable state analogous to superheated water. Eventually, this metastable state always decays by nucleating bubbles of the stable, stressfree, solid by a process very similar to how bubbles of steam appear in a kettle of boiling water. This fresh conceptual viewpoint curiously allows us to study failure of perfect crystalline solids in quantitative detail without invoking specifics of manybody, defect–defect interactions, raising hope of a more unified description of materials in the future. [1] Nath et al. PNAS 115 E4322E4329 (2018) 

16:30 to 17:30    Discussion 
Time  Speaker  Title  Resources  

11:10 to 12:00  Hisao Hayakawa 
The characterization of dense jammed matter: mutual relationships among the shearjammed, fragile states and the discontinuous shear thickening The mechanical response of twodimensional frictional granular materials under an oscillatory shear in a constant volume are numerically investigated. It is confirmed that the shear storage modulus G′ depends on the initial amplitude of the oscillation to prepare the system before the measurement. For sufficiently large initial strain amplitude, the shear jammed state satisfying G′ > 0 is observed even if the packing fraction is below the jamming point. The fragile state is also identified as a long lived metastable state where G′ depends on the phase of the oscillatory shear. The dynamic viscosity evaluated from the shear loss modulus G′′ exhibits a sudden jump similar to the discontinuous shear thickening in the fragile state. In this talk we also show some preliminary results of hydrodynamic simulation for colloidal suspensions to discuss shear jamming and DST as well as the behavior of dry granular particles under the pressure control protocol. 
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11:10 to 12:00  Srikanth Sastry 
Yielding in amorphous solids The loss of rigidity in amorphous solids when subjected to external stress has been investigated actively in recent years. I will describe recent results regarding the nature of the yielding transition, including strain localisation in the yielded solid, annealing effects below and above the yielding threshold, obtained by computational investigations of amorphous solids subjected to oscillatory deformation. 
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11:10 to 12:30  Subir Das 
Phase Transitions: Diversity in dynamics Following a general discussion on universalities related to various structural and dynamical aspects of phase transitions, I will concentrate on nonequilibrium phenomena. In this domain a set of problems will be described with the objective of highlighting how various aspects of coarsening phenomena depend upon space dimension, morphology, etc. Finally, I will present results from two problems of my current interest. One is related to kinetics of vaporsolid transitions and the other deals with the ordering in popular Ising ferromagnet. The aim will be to project the breadth of diversity even in simple situations. 
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11:10 to 12:30  Subhro Battacharjee 
Butterfly effect in classical spin systems Connections between manybody chaos and ergodicity form the basis of statistical mechanics. Starting with an overview of recent interests in this area, I shall discuss our numerical results characterising spatiotemporal signatures of chaos in spin systems and point out their possible quantitative connection to measures of transport such as diffusion coefficients. I shall discuss how the physics of frustration in classical spin systems help retain the signatures of chaos even at low temperatures. 
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11:10 to 12:30  Smarajit Karmakar 
Growth of Order and its role in the Dynamics of Supercooled Liquids Existence and growth of amorphous and other structural order in supercooled liquids approaching glass transition is a subject of intense research. Even after decades of work, there is still no clear consensus on the molecular mechanisms that lead to a rapid slowing down of liquid dynamics approaching this putative transition. The existence of a correlation length associated with amorphous order has recently been postulated and also been estimated using multipoint correlation functions which cannot be calculated easily in experiments. Thus the study of growing amorphous order remains mostly restricted to systems like colloidal glasses and simulations of model glassforming liquids. We proposed an experimentally realizable yet simple correlation function to study the growth of amorphous order. We then demonstrate the validity of this approach for a few wellstudied model supercooled liquids and obtain results, which are consistent with other conventional methods. Finally I will discuss role of the static lengthscale associated with this amorphous order in dynamics of glassy systems with medium range crystalline order. We tried to understand the molecular mechanisms for glass transition in liquids with and without medium range crystalline order. The issue is important to answer because if the liquid eventually starts to form crystalline domains while approaching the glass transition then the complexity of the problem may simplify and may just be governed by the physics of the growing crystalline order. If not then there exists a new class of glass forming materials whose molecular mechanism for slowing down of dynamics will probably be easier to understand in terms of the dynamics of the growing medium range crystalline order. We found evidence that dynamics of glasses with medium range crystalline order are generically different from other glass forming liquids with no predominant local order. Reference: 1. R Das, S Chakrabarty and S Karmakar, Soft Matter 13, 6929 (2017). 2. S Chakrabarty, I Tah, S Karmakar and C Dasgupta, PRL 119, 205502 (2017). 3. I Tah, S Sengupta, S Sastry, C Dasgupta and S Karmakar, PRL 121, 085703 (2018). 4. BP Bhowmik, I Tah and S Karmakar, PRE, 98, 022122 (2018)." 
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11:10 to 12:30  Pinaki Chaudhuri 
Response of glassy systems to quenched disorder Understanding how quenched disorder affects the glassy behaviour of materials has been of interest, for quite some time, for example, in the context of typeII superconductors, metallic alloys etc. More recently, specific constructions in the form of pinned particles, have been used to investigate the onset of slow dynamics and exploring the ideal glass transition scenario. In this context, using numerical studies, we will discuss two different situations : (a) the interplay of a simple glass forming liquid with a spatiallyvarying external potential, motivated by recent optical realisations & (b) yielding dynamics of a glass embedded with impurities. 
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11:10 to 12:30  Meher Prakash 
Mutual information for protein structure and dynamics Though the physical laws at the atomic level interactions of amino acids in proteins are well defined and simple, understanding how proteins work is nontrivial. Protein sequence > structure > dynamics is believed to be the key to the hierarchy of their functional organization. There are several gaps in this perspective which are being filled with informatic methods these days. For example, using large scale evolutionary data of sequences to predict the structure or to derive relationship with dynamics. One of the commonly used tools for this purpose is mutual information. The lecture will cover the basics of this informatic method as well as its implications to the understanding of proteins. 