Ozawa et. al [1] presented numerical results for the configurational entropy density, $s_c$, of a model glass-forming liquid in the presence of random pinning. The location of a "phase boundary" in the pin density ($c$) - temperature ($T$) plane, that separates an "ideal glass" phase from the supercooled liquid phase, is obtained by finding the points at which $s_c(T,c) \to 0$. According to the theoretical arguments by Cammarota et. al. [2], an ideal glass transition at which the $α$-relaxation time $τ_α$ diverges takes place when $s_c$ goes to zero. We have studied the dynamics of the same system using molecular dynamics simulations. We have calculated the time-dependence of the self intermediate scattering function, $F_s(k,t)$ at three state points in the $(c-T)$ plane where $s_c(T,c) \simeq 0$ according to Ref. [1]. It is clear from the plots that the relaxation time is finite [$τ_α\sim \mathcal{O}(10^6)]$ at these state points. Similar conclusions have been obtained in Ref.[3] where an overlap function was used to calculate $τ_α$ at these state points.
We propose a computational method to measure the configurational entropy in generic polydisperse glass-formers. In particular, our method resolves issues related to the diverging mixing entropy term due to a continuous polydispersity. The configurational entropy is measured as the difference between the well-defined fluid entropy and a more problematic glass entropy. We show that the glass entropy can be computed by a simple generalisation of the Frenkel-Ladd thermodynamic integration method, which includes permutations of the particle diameters. This approach automatically provides a physical…
We discuss the need for discretization to evaluate the configurational entropy in a general model. We also discuss the prescription using restricted partition function formalism to study the stationary limit of metastable states. We introduce a lattice model of dimers as a paradigm of molecular fluid and study metastability in it to investigate the root cause of glassy behavior. We demonstrate the existence of the entropy crisis in metastable states, from which it follows that the entropy crisis is the root cause underlying the ideal glass transition in systems with particles of all sizes. The…
The configurational entropy is one of the most important thermodynamic quantities characterizing supercooled liquids approaching the glass transition. Despite decades of experimental, theoretical, and computational investigation, a widely accepted definition of the configurational entropy is missing, its quantitative characterization remains fraud with difficulties, misconceptions and paradoxes, and its physical relevance is vividly debated. Motivated by recent computational progress, we offer a pedagogical perspective on the configurational entropy in glass-forming liquids. We first explain w…
We combine population annealing Monte Carlo and several thermodynamic integration techniques to measure equilibrium vibrational and configurational entropies in the metastable fluid regime beyond the dynamic glass transition. We obtain results for a three-dimensional binary mixture hard sphere system. Our results suggest that the configurational entropy vanishes before the equilibrium pressure diverges, which implies that an underlying thermodynamic glass transition exists for this system. The computational methods are general and can be applied to a variety of glass forming systems but are re…
Glass is an under-cooled liquid that very slowly relaxes towards the equilibrium crystalline state. Its energy balance is ill understood, since it is widely believed that the glassy state cannot be described thermodynamically. However, the classical paradoxes involving the Ehrenfest relations and Prigogine-Defay ratio can be explained when the `effective' or `fictive' temperature of the slow modes is taken as additional system parameter. Having straigtened out the proper picture, it is interesting to reconsider glass from a thermodynamic viewpoint. A shard of glass, kept at fixed temperature a…
We propose a new method to compute the configurational entropy of glassy systems as a function of the free energy of valleys at a given temperature, in the framework of the Stillinger and Weber approach. In this method, which we call free-energy inherent structures (FEIS) approach, valleys are represented by inherent structures that are statistically grouped according to their free-energy rather than the energy as is commonly done in the standard procedure. The FEIS method provides a further step toward a description of the relaxational behavior of glassy systems in terms of a free energy meas…
We consider the effect of droplet excitations in the random first order transition theory of glasses on the configurational entropy. The contribution of these excitations is estimated both at and above the ideal glass transition temperature. The temperature range where such excitations could conceivably modify or `round-out' an underlying glass transition temperature is estimated, and found to depend strongly on the surface tension between locally metastable phases in the supercooled liquid. For real structural glasses this temperature range is found to be very narrow, consistent with the quan…
Pinning a fraction of particles from an equilibrium configuration in supercooled liquids has been recently proposed as a way to induce a new kind of glass transition, the Random Pinning Glass Transition (RPGT). The RPGT has been predicted to share some features of standard thermodynamic glass transitions and usual first order ones. Thanks to its special nature, the approach and the study of the RPGT appears to be a fairly reachable task compared to the daunting problem of inspecting standard glass transitions. In this Letter we generalize the pinning particle procedure. We study a mean-field s…
The inherent structure approach, wherein thermodynamic and structural changes in glass forming liquids are analyzed in terms of local potential energy minima that the liquid samples, has recently been applied extensively to the study of thermodynamic aspects of glass forming liquids. The evalation of the configurational entropy, which arises from the multiplicity of local energy minima, plays a central role in such analyses. Results are presented here concerning the calculation of configurational entropy based on computer simulations of a model liquid, and the application of the inherent struc…
The configurational entropy is among the key observables to characterize experimentally the formation of a glass. Physically, it quantifies the multiplicity of metastable states in which an amorphous material can be found at a given temperature, and its temperature dependence provides a major thermodynamic signature of the glass transition, which is experimentally accessible. Measurements of the configurational entropy require, however, some approximations which have often led to ambiguities and contradictory results. Here we implement a novel numerical scheme to measure the configurational en…
Truly stable metastable states are an artifact of the mean-field approximation or the zero temperature limit. If such appealing concepts in glass theory as configurational entropy are to have a meaning beyond these approximations, one needs to cast them in a form involving states with finite lifetimes. Starting from elementary examples and using results of Gaveau and Schulman, we propose a simple expression for the configurational entropy and revisit the question of taking flat averages over metastable states. The construction is applicable to finite dimensional systems, and we explicitly show…
The effects of randomly pinning particles in a model glass-forming fluid are studied, with a focus on the dynamically heterogeneous relaxation in the presence of pinning. We show how four-point dynamical correlations can be analysed in real space, allowing direct extraction of a length scale that characterises dynamical heterogeneity. In the presence of pinning, the relaxation time of the glassy system increases by up to two decades, but there is almost no increase in either the four-point correlation length or the strength of the four-point correlations. We discuss the implications of these r…
A system is glassy when the observation time is much smaller than the equilibration time. A unifying thermodynamic picture of the glassy state is presented. Slow configurational modes are in quasi-equilibrium at an effective temperature. It enters thermodynamic relations with the configurational entropy as conjugate variable. Slow fluctuations contribute to susceptibilities via quasi-equilibrium relations, while there is also a configurational term. Fluctuation-dissipation relations also involve the effective temperature. Fluctuations in the energy are non-universal, however. The picture is su…
Liquids relax extremely slowly upon approaching the glass state. One explanation is that an entropy crisis, due to the rarefaction of available states, makes it increasingly arduous to reach equilibrium in that regime. Validating this scenario is challenging, because experiments offer limited resolution, while numerical studies lag more than eight orders of magnitude behind experimentally-relevant timescales. In this work we not only close the colossal gap between experiments and simulations but manage to create in-silico configurations that have no experimental analog yet. Deploying a range o…
It is frequently assumed that in the limit of vanishing cooling rate, the glass transition phenomenon becomes a thermodynamic transition at a temperature $T_{K}$. However, with any finite cooling rate, the system falls out of equilibrium at temperatures near $T_g(>T_{K})$, implying that the very existence of the putative thermodynamic phase transition at $T_{K}$ can be questioned. Recent studies of systems with randomly pinned particles have hinted that the thermodynamic glass transition may be observed in simulations and experiments carried out for liquids with randomly pinned particles. This…
Glass is a microscopically disordered, solid form of matter that results when a fluid is cooled or compressed in such a fashion that it does not crystallise. Almost all types of materials are capable of glass formation -- polymers, metal alloys, and molten salts, to name a few. Given such diversity, organising principles which systematise data concerning glass formation are invaluable. One such principle is the classification of glass formers according to their fragility\cite{fragility}. Fragility measures the rapidity with which a liquid's properties such as viscosity change as the glassy sta…
Classical particle systems characterized by continuous size polydispersity, such as colloidal materials, are not straightforwardly described using statistical mechanics, since fundamental issues may arise from particle distinguishability. Because the mixing entropy in such systems is divergent in the thermodynamic limit we show that the configurational entropy estimated from standard computational approaches to characterize glassy states also diverges. This reasoning would suggest that polydisperse materials cannot undergo a glass transition, in contradiction to experiments. We explain that th…
We propose and use a novel, hybrid Monte Carlo algorithm that combines configurational bias particle swaps with parallel tempering. We use this new method to simulate a standard model of a glass forming binary mixture above and below the so-called mode-coupling temperature, Tmct. We find that an ansatz that was used previously to extrapolate thermodynamic quantities to temperatures below Tmct breaks down in the vicinity of the mode-coupling temperature. Thus, previous estimates of the so-called Kauzmann temperature need to be reexamined. Also, we find that the Adam-Gibbs relations D ~ exp(-a/T…
The breakdown of crystalline order in a disordered background connects to some of the most challenging problems in condensed matter physics. For a superconducting vortex lattice, the equilibrium state in the presence of impurities is predicted to be a "Bragg glass" (BG), where the local crystalline order is maintained everywhere and yet the global positional order decays algebraically. Here, using scanning tunnelling spectroscopy (STS) we image the vortex lattice in a weakly pinned NbSe2 single crystal. We present direct evidence that the ordered state of the VL is a BG, consisting of a large …
When a liquid is cooled below its melting temperature, if crystallization is avoided, it forms a glass. This phenomenon, called glass transition, is characterized by a marked increase of viscosity, about 14 orders of magnitude, in a narrow temperature interval. The microscopic mechanism behind the glass transition is still poorly understood. However, recently, great advances have been made in the identification of cooperative rearranging regions, or dynamical heterogeneities, i.e. domains of the liquid whose relaxation is highly correlated. The growth of the size of these domains is now believ…
We review recent developments in structural-dynamical phase transitions in trajectory space. An open question is how the dynamic facilitation theory of the glass transition may be reconciled with thermodynamic theories that posit a vanishing configurational entropy. Dynamic facilitation theory invokes a dynamical phase transition, between an active phase (close to the normal liquid) and an inactive phase which is glassy, whose order parameter is either dynamic or a time-averaged structural quantity. In particular, the dynamical phase transition in systems with non-trivial thermodynamics manife…
We use computer simulations to study the thermodynamic properties of a glass former in which a fraction $c$ of the particles has been permanently frozen. By thermodynamic integration, we determine the Kauzmann, or ideal glass transition, temperature $T_K(c)$ at which the configurational entropy vanishes. This is done without resorting to any kind of extrapolation, {\it i.e.}, $T_K(c)$ is indeed an equilibrium property of the system. We also measure the distribution function of the overlap, {\it i.e.}, the order parameter that signals the glass state. We find that the transition line obtained f…
A theory which uses data of the static pair-correlation function is developed to calculate quantities associated with the viscous slowing down of supercooled liquids. We calculate value of the energy fluctuations that determine the number of stable bonds a particle forms with neighbors from data of the structural relaxation time. The number of bonds and the activation energy for relaxation are shown to increase sharply in a narrow temperature range close to the glass temperature. The configurational entropy calculated from values of the configurational fluctuations is found in good agreement w…
A popular Adam--Gibbs scenario has suggested that the excess entropy of glass and liquid over crystal dominates the dynamical arrest at the glass transition with exclusive contribution from configurational entropy over vibrational entropy. However, an intuitive structural rationale for the emergence of frozen dynamics in relation to entropy is still lacking. Here we study these issues by atomistically simulating the vibrational, configurational, as well as total entropy of a model glass former over their crystalline counterparts for the entire temperature range spanning from glass to liquid. B…
We study the growing time scales and length scales associated with dynamical slow down for a realistic glass former, using computer simulations. We perform finite size scaling to evaluate a length scale associated with dynamical heterogeneity which grows as temperature decreases. However, relaxation times which also grow with decreasing temperature, do not show the same kind of scaling behavior with system size as the dynamical heterogeneity, indicating that relaxation times are not solely determined by the length scale of dynamical heterogeneity. We show that relaxation times are instead dete…
The vortex lattice in a Type II superconductor provides a versatile model system to investigate the order-disorder transition in a periodic medium in the presence of random pinning. Here, using scanning tunnelling spectroscopy in a weakly pinned Co0.0075NbSe2 single crystal, we show that at low temperatures, the vortex lattice in a 3-dimensional superconductor disorders in two steps across the peak effect. At the onset of the peak effect, the equilibrium Bragg glass transforms into an orientational glass through the proliferation of dislocations. At a higher field, the dislocations dissociate …
We demonstrate that there is no ideal glass transition in a binary hard-disk mixture by explicitly constructing an exponential number of jammed packings with densities spanning the spectrum from the accepted ``amorphous'' glassy state to the phase-separated crystal. Thus the configurational entropy cannot be zero for an ideal amorphous glass, presumed distinct from the crystal in numerous theoretical and numerical estimates in the literature. This objection parallels our previous critique of the idea that there is a most-dense random (close) packing for hard spheres [Torquato et al, Phys. Rev.…
We consider ``lattice glass models'' in which each site can be occupied by at most one particle, and any particle may have at most l occupied nearest neighbors. Using the cavity method for locally tree-like lattices, we derive the phase diagram, with a particular focus on the vitreous phase and the highest packing limit. We also study the energy landscape via the configurational entropy, and discuss different equilibrium glassy phases. Finally, we show that a kinetic freezing, depending on the particular dynamical rules chosen for the model, can prevent the equilibrium glass transitions.
The viscous slowing down of supercooled liquids that leads to glass formation can be considered as a classical, and is assuredly a thoroughly studied, example of a "jamming process". In this review, we stress the distinctive features characterizing the phenomenon. We also discuss the main theoretical approaches, with an emphasis on the concepts (free volume, dynamic freezing and mode-coupling approximations, configurational entropy and energy landscape, frustration) that could be useful in other areas of physics where jamming processes are encountered.
We reformulate the interpretation of the mean-field glass transition scenario for finite dimensional systems, proposed by Wolynes and collaborators. This allows us to establish clearly a temperature dependent length xi* above which the mean-field glass transition picture has to be modified. We argue in favor of the mosaic state introduced by Wolynes and collaborators, which leads to the Adam-Gibbs relation between the viscosity and configurational entropy of glass forming liquids. Our argument is a mixture of thermodynamics and kinetics, partly inspired by the Random Energy Model: small cluste…
New experimental data are presented on the scan rate dependence of the magnetization hysteresis width $ΔM(H)$ ($\propto$ critical current density $J_c(H)$) in isothermal $M-H$ scans in a weakly pinned single crystal of Ca$_3$Rh$_4$Sn$_{13}$, which displays second magnetization peak (SMP) anomaly as distinct from the peak effect (PE). We observe an interesting modulation in the field dependence of a parameter which purports to measure the dynamical annealing of the disordered bundles of vortices injected through the sample edges towards the destined equilibrium vortex state at a given $H$. Thes…
The description of activated relaxation of glassy systems in the multidimensional configurational space is a long-standing open problem. We develop a phenomenological description of the out-of-equilibrium dynamics of a model with a rough potential energy landscape and we analyse it both numerically and analytically. The model provides an example of dynamics where typical relaxation channels go over finite potential energy barriers despite the presence of less-energy-demanding escaping paths in configurational space; we expect this phenomenon to be also relevant in the thermally activated regim…
We present a new phase-field model for binary fluids exhibiting typical signatures of self-glassiness, such as long-time relaxation, ageing and long-term dynamical arrest. The present model allows the cost of building an interface to become locally zero, while preserving global positivity of the overall surface tension. An important consequence of this property, which we prove analytically, is the emergence of compact configurations of fluid density. Owing to their finite-size support, these "compactons" can be arbitrarily superposed, thereby providing a direct link between the ruggedness of t…
Computer simulations have been employed in recent years to evaluate the configurational entropy changes in model glass-forming liquids. We consider two methods, both of which involve the calculation of the `intra-basin' entropy as a means for obtaining the configurational entropy. The first method involves the evaluation of the intra-basin entropy from the vibrational frequencies of inherent structures, by making a harmonic approximation of the local potential energy topography. The second method employs simulations that confine the liquid within a localized region of configuration space by th…
The Adam-Gibbs (AG) relation connects the dynamics of a glass-forming liquid to its the thermodynamics via. the configurational entropy, and is of fundamental importance in descriptions of glassy behaviour. The breakdown of the Stokes-Einstein (SEB) relation between the diffusion coefficient and the viscosity (or structural relaxation times) in glass formers raises the question as to which dynamical quantity the AG relation describes. By performing molecular dynamics simulations, we show that the AG relation is valid over the widest temperature range for the diffusion coefficient and not for t…
We have computed the time-dependent susceptibility for the finite-size mean-field Random Orthogonal model (ROM). We find that for temperatures above the mode-coupling temperature the imaginary part of the susceptibility $χ''(ν)$ obeys the scaling forms proposed for glass-forming liquids. Furthermore, as the temperature is lowered the peak frequency of $χ''$ decreases following a Vogel-Fulcher law with a critical temperature remarkably close to the known critical temperature $T_c$ where the configurational entropy vanishes.
For the dynamical glassy transition in the $p$-spin mean field spin glass model a thermodynamic description is given. The often considered marginal states are not the relevant ones for this purpose. This leads to consider a cooling experiment on exponential timescales, where lower states are accessed. The very slow configurational modes are at quasi-equilibrium at an effective temperature. A system independent law is derived that expresses their contribution to the specific heat. $t/t_w$-scaling in the aging regime of two-time quantities is explained.
Recently, some of us developed a novel model glass-forming liquid with k extra interactions with pseudo neighbours to each liquid particle over and above the regular interactions with its neighbours. Analysis of the structure and dynamics of these systems showed that with an increase in k the systems have more mean-field like properties. This work presents an extensive study of the thermodynamics of the above-mentioned model for several values of k and its correlation with the dynamics. We surprisingly find that the usual thermodynamic integration (TI) method of calculating the entropy provide…
We study the high temperature regime within the glass phase of an elastic object with short ranged disorder. In that regime we argue that the scaling functions of any observable are described by a continuum model with a $δ$-correlated disorder and that they are universal up to only two parameters that can be explicitly computed. This is shown numerically on the roughness of directed polymer models and by dimensional and functional renormalization group arguments. We discuss experimental consequences such as non-monotonous behaviour with temperature.
In order to find out whether there exists a thermodynamic description of the glass phase, the Ehrenfest relations along the glass transition line are reconsidered. It is explained that the one involving the compressibility is always satisfied, and that the one involving the specific heat is principally incorrect. Thermodynamical relations are presented for non-ergodic systems with a one-level tree in phase space. They are derived for a spin glass model, checked for other models, and expected to apply, e.g., to glass forming liquids. The second Ehrenfest relation gets a contribution from the co…
How the vortex lattice orders at long range in a layered superconductor with weak point pinning centers is studied through a duality analysis of the corresponding frustrated XY model. Vortex-glass order emerges out of the vortex liquid across a macroscopic number of weakly coupled layers in perpendicular magnetic field as the system cools down. Further, the naive magnetic-field scale determined by the Josephson coupling between adjacent layers is found to serve as an upperbound for the stability of any possible conventional vortex lattice phase at low temperature in the extreme type-II limit.
The repulsive term of Van der Waals equation of state has been deduced and improved in this work using a probabilistic description of the configurational entropy. The aim is to find out whether its physical basis is suitable for the study of dense fluids like liquids and glasses. The extended Van der Waals model accurately describes a system composed of independent Hard Spheres below packing fraction η < 0.3, giving a pole at η ~ 0.51 in close agreement with Molecular Dynamic simulation results. The inclusion of holes in the configurational entropy description improves the model but only below…
We show in numerical simulations that a system of two coupled replicas of a binary mixture of hard spheres undergoes a phase transition in equilibrium at a density slightly smaller than the glass transition density for an unreplicated system. This result is in agreement with the theories that predict that such a transition is a precursor of the standard ideal glass transition. The critical properties are compatible with those of an Ising system. The relations of this approach to the conventional approach based on configurational entropy are briefly discussed.
We generalize the force-level, microscopic, Nonlinear Langevin Equation (NLE) theory and its elastically collective generalization (ECNLE theory) of activated dynamics in bulk spherical particle liquids to address the influence of random particle pinning on structural relaxation. The simplest neutral confinement model is analyzed for hard spheres where there is no change of the equilibrium pair structure upon particle pinning. As the pinned fraction grows, cage scale dynamical constraints are intensified in a manner that increases with density. This results in the mobile particles becoming mor…
We report constant-volume and constant-pressure simulations of the thermodynamic and dynamic properties of the low-temperature liquid and crystalline phases of the modified Stillinger-Weber (mSW) model. We have found an approximately linear increase of the effective Gaussian width of the distribution of inherent structures. This effect comes from non-Gaussianity of the landscape and is consistent with the predictions of the Gaussian excitations model representing the thermodynamics of the configurational manifold as an ensemble of excitations, each carrying an excitation entropy. The mSW model…
The fluctuation-dissipation theorem (FDT), connecting dielectric susceptibility and polarization noise was studied in glycerol below its glass transition temperature Tg. Weak FDT violations were observed after a quench from just above to just below Tg, for frequencies above the alpha peak. Violations persisted up to 10^5 times the thermal equilibration time of the configurational degrees of freedom under study, but comparable to the average relaxation time of the material. These results suggest that excess energy flows from slower to faster relaxing modes.
We investigate numerically the low temperature equilibration of glassy systems via non-local Monte Carlo methods. We re-examine several systems that have been studied previously and investigate new systems in order to test the performance of such methods near the putative Kauzmann temperature, $T_K$, where the configurational entropy is presumed to vanish. Our results suggest that previous numerical claims in favor of and against a thermodynamic transition at a finite $T_K$ must be re-evaluated. Our work provides some guidelines and suggestions for future numerical investigations of disordered…
Using RG we investigate the non-equilibrium relaxation of the (Cardy-Ostlund) 2D random Sine-Gordon model, which describes pinned arrays of lines. Its statics exhibits a marginal ($θ=0$) glass phase for $T<T_g$ described by a line of fixed points. We obtain the universal scaling functions for two-time dynamical response and correlations near $T_g$ for various initial conditions, as well as the autocorrelation exponent. The fluctuation dissipation ratio is found to be non-trivial and continuously dependent on $T$.
Generation of equilibrium configurations is the major obstacle for numerical investigation of the slow dynamics in supercooled liquid states. The parallel tempering (PT) technique, originally proposed for the numerical equilibration of discrete spin-glass model configurations, has recently been applied in the study of supercooled structural glasses. We present an investigation of the ability of parallel tempering to properly sample the liquid configuration space at different temperatures, by mapping the PT dynamics into the dynamics of the closest local potential energy minima (inherent struct…
We calculate the density of states of a binary Lennard-Jones glass using a recently proposed Monte Carlo algorithm. Unlike traditional molecular simulation approaches, the algorithm samples distinct configurations according to self-consistent estimates of the density of states, thereby giving rise to uniform internal-energy histograms. The method is applied to simulate the equilibrium, low-temperature thermodynamic properties of a widely studied glass former consisting of a binary mixture of Lennard-Jones particles. We show how a density-of-states algorithm can be combined with particle identi…
We study the effects of random pinning on the Fredrickson-Andersen model on the Bethe lattice. We find that the nonergodic transition temperature rises as the fraction of the pinned spins increases and the transition line terminates at a critical point. The freezing behavior of the spins is analogous to that of a randomly pinned p-spin mean-field spin glass model which has been recently reported. The diverging behavior of correlation lengths in the vicinity of the terminal critical point is found to be identical to the prediction of the inhomogeneous mode-coupling theory at the A3 singularity …
We have studied metastability effects pertaining to the peak effect (PE) in critical current density ($J_c$) via isofield scans in ac susceptibility measurements in a weakly pinned single crystal of Yb$_3$Rh$_4$Sn$_{13}$ ($T_c(0) \approx 7.6 $~K). The order-disorder transition in this specimen proceeds in a multi-step manner. The phase coexistence regime between the onset temperature of the PE and the spinodal temperature (where metastability effects cease) seems to comprise two parts, where ordered and disordered regions dominate the bulk behavior, respectively. The PE line in the vortex phas…
We investigate the replica theory of the liquid-glass transition for a binary mixture of large and small additive hard spheres. We consider two different ansätze for this problem: the frozen glass ansatz (FGA) in whichs the exchange of large and small particles in a glass state is prohibited, and the exchange glass ansatz (EGA), in which it is allowed. We calculate the dynamical and thermodynamical glass transition points with the two ansätze. We show that the dynamical transition density of the FGA is lower than that of the EGA, while the thermodynamical transition density of the FGA is highe…
Tackling the low-temperature fate of supercooled liquids is challenging due to the immense timescales involved, which prevent equilibration and lead to the operational glass transition. Relating glassy behaviour to an underlying, thermodynamic phase transition is a long-standing open question in condensed matter physics. Like experiments, computer simulations are limited by the small time window over which a liquid can be equilibrated. Here we address the challenge of low temperature equilibration using trajectory sampling in a system undergoing a nonequilibrium phase transition. This transiti…
We perform stringent tests of thermodynamic theories of the glass transition over the experimentally relevant temperature regime for several simulated glass-formers. The swap Monte Carlo algorithm is used to estimate the configurational entropy and static point-to-set lengthscale, and careful extrapolations are used for the relaxation times. We first quantify the relation between configurational entropy and the point-to-set lengthscale in two and three dimensions. We then show that the Adam-Gibbs relation is generally violated in simulated models for the experimentally relevant time window. Co…
