arXiv subjects

Yuliang Jin

Publications and source records attributed to Yuliang Jin.

At least 37 records · Page 2Linked to original sources

arXiv2024

Gardner transition coincides with the emergence of jamming scalings in hard spheres and disks

The Gardner transition in structural glasses is characterized by full-replica symmetry breaking of the free-energy landscape and the onset of anomalous aging dynamics due to marginal stability. Here we show that this transition also has a structural signature in finite-dimensional glasses consisting of hard spheres and disks. By analyzing the distribution of inter-particle gaps in the simulated static configurations at different pressures, we find that the Gardner transition coincides with the emergence of two well-known jamming scalings in the gap distribution, which enables the extraction of a structural order parameter. The jamming scalings reflect a compressible effective force network formed by contact and quasi-contact gaps, while non-contact gaps that do not participate in the effective force network are incompressible. Our results suggest that the Gardner transition in hard-particle glasses is a precursor of the jamming transition. The proposed structural signature and order parameter provide a convenient approach to detecting the Gardner transition in future granular experiments.

cond-mat.soft↗

arXiv2024

Jamming is a first-order transition with quenched disorder in amorphous materials sheared by cyclic quasistatic deformations

Jamming is an athermal transition between flowing and rigid states in amorphous systems such as granular matter, colloidal suspensions, complex fluids and cells. The jamming transition seems to display mixed aspects of a first-order transition, evidenced by a discontinuity in the coordination number, and a second-order transition, indicated by power-law scalings and diverging lengths. Here we demonstrate that jamming is a first-order transition with quenched disorder in cyclically sheared systems with quasistatic deformations, in two and three dimensions. Based on scaling analyses, we show that fluctuations of the jamming density in finite-sized systems have important consequences on the finite-size effects of various quantities, resulting in a square relationship between disconnected and connected susceptibilities, a key signature of the first-order transition with quenched disorder. This study puts the jamming transition into the category of a broad class of transitions in disordered systems where sample-to-sample fluctuations dominate over thermal fluctuations, suggesting that the nature and behavior of the jamming transition might be better understood within the developed theoretical framework of the athermally driven random-field Ising model.

cond-mat.soft↗

arXiv2024

Thermodynamic crossovers in supercritical fluids

Can liquid-like and gas-like states be distinguished beyond the critical point, where the liquid-gas phase transition no longer exists and conventionally only a single supercritical fluid phase is defined? Recent experiments and simulations report strong evidence of dynamical crossovers above the critical temperature and pressure. Despite using different criteria, many existing theoretical explanations consider a single crossover line separating liquid-like and gas-like states in the supercritical fluid phase. We argue that such a single-line scenario is inconsistent with the supercritical behavior of the Ising model, which has two crossover lines due to its symmetry, violating the universality principle of critical phenomena. To reconcile the inconsistency, we define two thermodynamic crossover lines in supercritical fluids as boundaries of liquid-like, indistinguishable, and gas-like states. Near the critical point, the two crossover lines follow critical scalings with exponents of the Ising universality class, supported by calculations of theoretical models and analyses of experimental data from the standard database. The upper line agrees with crossovers independently estimated from the inelastic X-ray scattering data of supercritical argon, and from the small-angle neutron scattering data of supercritical carbon dioxide. The lower line is verified by the equation of states for the compressibility factor. This work provides a fundamental framework for understanding supercritical physics in general phase transitions.

cond-mat.stat-mech↗

arXiv2023

A review on shear jamming

Jamming is a ubiquitous phenomenon that appears in many soft matter systems, including granular materials, foams, colloidal suspensions, emulsions, polymers, and cells -- when jamming occurs, the system undergoes a transition from flow-like to solid-like states. Conventionally, the jamming transition occurs when the system reaches a threshold jamming density under isotropic compression, but recent studies reveal that jamming can also be induced by shear. Shear jamming has attracted much interest in the context of non-equilibrium phase transitions, mechanics and rheology of amorphous materials. Here we review the phenomenology of shear jamming and its related physics. We first describe basic observations obtained in experiments and simulations, and results from theories. Shear jamming is then demonstrated as a "bridge" that connects the rheology of athermal soft spheres and thermal hard spheres. Based on a generalized jamming phase diagram, a universal description is provided for shear jamming in frictionless and frictional systems. We further review the isostaticity and criticality of the shear jamming transition, and the elasticity of shear jammed solids. The broader relevance of shear jamming is discussed, including its relation to other phenomena such as shear hardening, dilatancy, fragility, and discrete shear thickening.

cond-mat.soft↗

arXiv2023

An intermediate phase between jammed and un-jammed amorphous solids

A significant amount of attention was dedicated in recent years to the phenomenon of jamming of athermal amorphous solids by increasing the volume fraction of the microscopic constituents. At a critical value of the volume fraction, pressure shoots up from zero to finite values with a host of critical exponents discovered and discussed. In this letter, we advance evidence for the existence of a second transition, within the jammed state of two-dimensional granular systems, that separates two phases characterized by different mechanical screening regimes. Explicitly, highly packed systems are quasi-elastic with quadrupole-screening, and more loosely jammed systems exhibit anomalous mechanics with dipole screening. Evidence is given for a clear transition between these two regimes, reminiscent of the intermediate hexatic phase of crystal melting in two-dimensional crystals.

cond-mat.soft↗

arXiv2023

The yielding of granular matter is marginally stable and critical

The mechanical yield of dense granular materials is a fascinating rheological phenomenon, beyond which stress no longer increases with strain at a sufficiently large deformation. Understanding the behavior of mechanical responses associated with yielding is a fundamental goal in granular physics, and other related fields including glassy physics, material sciences, geophysics, and active matter biophysics. However, despite nearly half a century of theoretical efforts, the nature of yielding in amorphous solids remains largely elusive compared to its crystalline counterpart. Here, we experimentally investigate the mechanical responses of two-dimensional bidisperse jammed disks subjected to volume-invariant pure shear, focusing on the behavior of yielding. We show that the microscopic mechanical and geometrical features of configurations under shear can be characterized by two critical exponents of weak-force and small-gap distributions originally proposed for the isotropic jamming transition. We find that the yielding transition satisfies the condition of marginal mechanical stability through a scaling relationship between the two exponents, and after yielding global instability emerges. The criticality of yielding is revealed by a significant peak of susceptibility that quantifies the fluctuation of a glass overlap order parameter. Moreover, we find a distinct transition before yielding, which is associated with the onset of structural anisotropy.

cond-mat.soft↗

arXiv2023

Shear hardening in frictionless amorphous solids near the jamming transition

The jamming transition, generally manifested by a rapid increase of rigidity under compression (i.e., compression hardening), is ubiquitous in amorphous materials. Here we study shear hardening in deeply annealed frictionless packings generated by numerical simulations, reporting critical scalings absent in compression hardening. We demonstrate that hardening is a natural consequence of shear-induced memory destruction. Based on an elasticity theory, we reveal two independent microscopic origins of shear hardening: (i) the increase of the interaction bond number and (ii) the emergence of anisotropy and long-range correlations in the orientations of bonds, the latter highlights the essential difference between compression and shear hardening. Through the establishment of physical laws specific to anisotropy, our work completes the criticality and universality of jamming transition, and the elasticity theory of amorphous solids.

cond-mat.soft↗

arXiv2022

Machine learning glass caging order parameters with an artificial nested neural network

Around a glass transition, the dynamics of a supercooled liquid dramatically slow down, exhibited by caging of particles, while the structural changes remain subtle. In alternative to recent machine learning studies searching for structural predictors of glassy dynamics, here we propose to learn directly particle caging features defined purely according to dynamics. We focus on three transitions in a simulated hard sphere glass model, the melting of ultra-stable glasses, the Gardner transition and the liquid to ordinary glass transition. Implementing the machine learning algorithm based on a two-level nested neural network, we attain not only proper caging order parameters for all three transitions, but also a phase classification for input samples. A finite-size scaling analysis of the phase classification results identifies the order of melting (first) and Gardner (second) transitions. A false positive is avoided, as the liquid to glass transition is indicated as a crossover, rather than a phase transition with a well-defined transition point. This study paves the way to a generic approach for learning dynamical features in glassy systems, with a minimum requirement of system-specific knowledge.

cond-mat.dis-nn↗

arXiv2022

Computer simulations of the Gardner transition in structural glasses

The exact mean-field theory for the simplest glass-forming system - the dense assembly of hard spheres in the large dimensional limit - predicts the existence of a Gardner phase. This transition is characterized by full replica symmetry breaking that implies two fascinating physical consequences: (i) a hierarchical free-energy landscape, and (ii) marginal stability. Here we discuss recent results of numerical simulations to examine these mean-field predictions in physical dimensions.

cond-mat.dis-nn↗

arXiv2022

Non-linear elasticity, yielding and entropy in amorphous solids

The holographic duality has proven successful in linking seemingly unrelated problems in physics.Recently, intriguing correspondences between the physics of soft matter and gravity are emerging,including strong similarities between the rheology of amorphous solids, effective field theories for elasticity and the physics of black holes. However, direct comparisons between theoretical predictions and experimental/simulation observations remain limited. Here, we study the effects of non-linear elasticity on the mechanical and thermodynamic properties of amorphous materials responding to shear, using effective field and gravitational theories. The predicted correlations among the non-linear elastic exponent, the yielding strain/stress and the entropy change due to shear are supported qualitatively by simulations of granular matter models. Our approach opens a path towards understanding complex mechanical responses of amorphous solids, such as mixed effects of shear softening and shear hardening, and offers the possibility to study the rheology of solid states and black holes in a unified framework.

cond-mat.soft↗

arXiv2022

Experimental observations of marginal criticality in granular materials

Two drastically different theories predict the marginal criticality of jamming. The full replica symmetry breaking (fullRSB) theory [1-4] predicts the power-law distributions of weak contact forces and small inter-particle gaps in infinite-dimensional hard-sphere glass, with two nontrivial exponents $θ_f=0.42311...$ and $γ=0.41269...$, respectively. While the marginal mechanical stability (MMS) analysis [5-8] predicts that the isostatic random packings of hard frictionless spheres under external stress are marginally stable and provides inequality relationships for the exponents of the weak-force and inter-particle-gap distributions. Here we measure precisely contact forces and particle positions in isotropic jammed bidisperse photoelastic disks and find the clear power-law distributions of weak forces and small inter-particle gaps, with both exponents $θ_f=0.44(2)$ and $γ= 0.43(3) $ in an excellent agreement with the fullRSB theory. As the jammed packing subject to area-conserved cyclic pure shear approaches the yielding point, the two exponents change substantially from those of the isotropic case but they still satisfy the scaling relationship provided by the MMS argument. Our results provide strong experimental evidences for the robustness of the infinite-dimensional theory and the MMS analysis in real-world amorphous materials.

cond-mat.soft↗

arXiv2021

A jamming plane of sphere packings

The concept of jamming has attracted great research interest due to its broad relevance in soft matter such as liquids, glasses, colloids, foams, and granular materials, and its deep connection to the sphere packing problem and optimization problems. Here we show that the domain of amorphous jammed states of frictionless spheres can be significantly extended, from the well-known jamming-point at a fixed density, to a jamming-plane that spans the density and shear strain axes. We explore the jamming-plane, via athermal and thermal simulations of compression and shear jamming, with a help of an efficient swap algorithm to prepare initial equilibrium configurations. The jamming-plane can be divided into reversible-jamming and irreversible-jamming regimes, based on the reversibility of the route from the initial configuration to jamming. Our results suggest that the irreversible-jamming behavior reflects an escape from the meta-stable glass basin to which the initial configuration belongs to, or the absence of such basins. All jammed states, either compression or shear jammed, are isostatic, and exhibit jamming criticality of the same universality class. However, the anisotropy of contact networks non-trivially depends on the jamming density and strain. Among all state points on the jamming-plane, the jamming-point is a unique one with the minimum jamming density and the maximum randomness. For lattice packings, the jamming-plane shrinks into a single shear jamming-line that is independent of initial configurations. Our study paves the way for solving the long-standing random close packing problem, and provides a more complete framework to understand jamming.

cond-mat.soft↗

arXiv2021

Determining the nonequilibrium criticality of a Gardner transition via a hybrid study of molecular simulations and machine learning

Apparent critical phenomena, typically indicated by growing correlation lengths and dynamical slowing-down, are ubiquitous in non-equilibrium systems such as supercooled liquids, amorphous solids, active matter and spin glasses. It is often challenging to determine if such observations are related to a true second-order phase transition as in the equilibrium case, or simply a crossover, and even more so to measure the associated critical exponents. Here, we show that the simulation results of a hard-sphere glass in three dimensions, are consistent with the recent theoretical prediction of a Gardner transition, a continuous non-equilibrium phase transition. Using a hybrid molecular simulation-machine learning approach, we obtain scaling laws for both finite-size and aging effects, and determine the critical exponents that traditional methods fail to estimate. Our study provides a novel approach that is useful to understand the nature of glass transitions, and can be generalized to analyze other non-equilibrium phase transitions.

cond-mat.soft↗

arXiv2020

Is friction essential for dilatancy and shear jamming in granular matter?

Granular packings display the remarkable phenomenon of dilatancy [1], wherein their volume increases upon shear deformation. Conventional wisdom and previous results suggest that dilatancy, as also the related phenomenon of shear-induced jamming, requires frictional interactions [2, 3]. Here, we investigate the occurrence of dilatancy and shear jamming in frictionless packings. We show that the existence of isotropic jamming densities ϕj above the minimal density, the J-point density ϕJ [4, 5], leads both to the emergence of shear-induced jamming and dilatancy. Packings at ϕJ form a significant threshold state into which systems evolve in the limit of vanishing pressure under constant pressure shear, irrespective of the initial jamming density ϕj. While packings for different ϕj display equivalent scaling properties under compression [6], they exhibit striking differences in rheological behaviour under shear. The yield stress under constant volume shear increases discontinuously with density when ϕj > ϕJ, contrary to the continuous behavior in generic packings that jam at ϕJ [4, 7].

cond-mat.stat-mech↗

arXiv2018

A stability-reversibility map unifies elasticity, plasticity, yielding and jamming in hard sphere glasses

Amorphous solids, such as glasses, have complex responses to deformations, with significant consequences in material design and applications. In this respect two intertwined aspects are important: stability and reversibility. It is crucial to understand on the one hand how a glass may become unstable due to increased plasticity under shear deformations; on the other hand, to what extent the response is reversible, meaning how much a system is able to recover the original configuration once the perturbation is released. Here we focus on assemblies of hard spheres as the simplest model of amorphous solids such as colloidal glasses and granular matter. We prepare glass states quenched from equilibrium supercooled liquid states, which are obtained by using the swap Monte Carlo algorithm and correspond to a wide range of structural relaxation time scales. We exhaustively map out their stability and reversibility under volume and shear strains, using extensive numerical simulations. The region on the volume-shear strain phase diagram where the original glass state remains solid is bounded by the shear-yielding and the shear-jamming lines which meet at a yielding-jamming crossover point. This solid phase can be further divided into two sub-phases: the stable glass phase where the system deforms purely elastically and is totally reversible, and the marginal glass phase where it experiences stochastic plastic deformations at mesoscopic scales and is partially irreversible. The details of the stability-reversibility map depend strongly on the quality of annealing of the glass. This study provides a unified framework for understanding elasticity, plasticity, yielding and jamming in amorphous solids.

cond-mat.soft↗

arXiv2018

Local structure can identify and quantify influential global spreaders in large scale social networks

Measuring and optimizing the influence of nodes in big-data online social networks are important for many practical applications, such as the viral marketing and the adoption of new products. As the viral spreading on social network is a global process, it is commonly believed that measuring the influence of nodes inevitably requires the knowledge of the entire network. Employing percolation theory, we show that the spreading process displays a nucleation behavior: once a piece of information spread from the seeds to more than a small characteristic number of nodes, it reaches a point of no return and will quickly reach the percolation cluster, regardless of the entire network structure, otherwise the spreading will be contained locally. Thus, we find that, without the knowledge of entire network, any nodes' global influence can be accurately measured using this characteristic number, which is independent of the network size. This motivates an efficient algorithm with constant time complexity on the long standing problem of best seed spreaders selection, with performance remarkably close to the true optimum.

physics.soc-ph↗

arXiv2017

Exploring the complex free energy landscape of the simplest glass by rheology

For amorphous solids, it has been intensely debated whether the traditional view on solids, in terms of the ground state and harmonic low energy excitations on top of it, such as phonons, is still valid. Recent theoretical developments of amorphous solids revealed the possibility of unexpectedly complex free energy landscapes where the simple harmonic picture breaks down. Here we demonstrate that standard rheological techniques can be used as powerful tools to examine non-trivial consequences of such complex free energy landscapes. By extensive numerical simulations on a hard sphere glass under quasi-static shear at finite temperatures, we show that, above the so-called Gardner transition density, the elasticity breaks down, the stress relaxation exhibits slow and aging dynamics, and the apparent shear modulus becomes protocol-dependent. Being designed to be reproducible in laboratories, our approach may trigger explorations of the complex free energy landscapes of a large variety of amorphous materials.

cond-mat.soft↗

arXiv2017

Equation of state for random sphere packing with arbitrary adhesion and friction

We systematically generate a large set of random micro-particle packings over a wide range of adhesion and friction by means of adhesive contact dynamics simulation. The ensemble of generated packings covers a range of volume fraction $ϕ$ from $0.135 \pm 0.007$ to $0.639 \pm 0.004$, and of coordination number $Z$ from $2.11 \pm 0.03$ to $6.40 \pm 0.06$. We determine $ϕ$ and $Z$ at four limits (random close packing, random loose packing, adhesive close packing, and adhesive loose packing), and find a universal equation of state $ϕ(Z)$ to describe packings with arbitrary adhesion and friction. From a mechanical equilibrium analysis, we determine a critical friction coefficient $μ_{\rm f, c}$: when the friction coefficient $μ_{\rm f}$ is below $μ_{\rm f, c}$, particles' rearrangements are dominated by sliding, otherwise, they are dominated by rolling. Because of this reason, both $ϕ(μ_{\rm f})$ and $Z(μ_{\rm f})$ change sharply across $μ_{\rm f, c}$. Finally, we generalize the Maxwell counting argument to micro-particle packings, and show that the loosest packing, i.e., adhesive loose packing, satisfies the isostatic condition at $Z=2$.

cond-mat.soft↗