Research
Glass and Gardner transitions
Numerical studies of the Gardner transition in hard sphere glasses
Recent advances in the mean-field theory of glasses have predicted the existence, deep into the glass phase, of a novel phase transition, the so-called Gardner transition. This critical phase transition is associated to the emergence of a fractal free-energy landscape and marginal stability of the glass states. However, the relevance of Gardner transition to physical systems in two or three dimensions was unclear. We studied numerically the Gardner transition in structural glass models, and related this transition to glass anomalies including, onset of aging in ultra-stable glasses, emergence of spatial heterogeneity of particles’ vibrational dynamics, and breakdown of elasticity.
Y. Jin and H. Yoshino, Exploring the complex free energy landscape of the simplest glass by rheology, Nat. Commun. 8, 14935 (2017).
L. Berthier, P. Charbonneau, Y. Jin, G. Parisi, B. Seoane, and F. Zamponi, Growing timescales and lengthscales characterizing vibrations of amorphous solids, PNAS 113, 8397-8401 (2016).
P. Charbonneau, Y. Jin, G. Parisi, C. Rainone, B. Seoane, and F. Zamponi, Numerical detection of the Gardner transition in a mean-field glass former, Phys. Rev. E 92, 012316 (2015).
Jamming transition and sphere packing problem
A jamming plane of sphere packings
Jamming is a ubiquitous phenomenon that occurs when the viscosity diverges or the rigidity emerges in many soft matter systems, such as granular materials, glasses, foams, colloidal suspensions, emulsions, and polymers. Jamming of frictionless spheres is also closely related to the sphere packing and optimization problems. In practice, jammed packings can be obtained by various ways, among which, compression and shear are two widely employed protocols. We demonstrate that compression and shear-jammed frictionless packings can be described under a unified framework called ''jamming-plane". Using computer simulations, we show that compression and shear jamming of frictionless spheres can occur at different densities in the limit of large systems, contrary to conventional wisdom, but the jamming criticality is protocol-independent.
Y. Jin and H. Yoshino, A jamming plane of sphere packings, PNAS 118, e2021794118 (2021).
Rheology of amorphous solids
A stability map of hard sphere glasses
Hard spheres are often used as the simplest model of amorphous solids such as colloidal glasses and granular matter. Using computer simulations, we studied the response of a hard sphere glass to volume and shear strains. As a result, we obtained a stability-reversibility map which unifies elasticity, plasticity, yielding, and jamming in the hard sphere glass model.
Y. Jin, P. Urbani, F. Zamponi, and H. Yoshino, A stability-reversibility map unifies elasticity, plasticity, yielding, and jamming in hard sphere glasses, Sci. Adv. 4, eaat6387 (2018).
A holographic approach for nonlinear elasticity 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. We study the effects of nonlinear elasticity on the mechanical and thermodynamic properties of amorphous materials responding to shear, using effective field and gravitational theories.
D. Pan, T. Ji, M. Baggioli, L. Li, and Y. Jin, Nonlinear elasticity, yielding, and entropy in amorphous solids, Science Advances 8, eabm8028 (2022).
Machine learning soft matter
Machine learning the Gardner transition in a hard sphere glass
Understanding the nature of glass states remains as one of the grand challenges presently. A much-debated issue is whether or not a glass-to-glass transition, the Gardner transition, occurs in deeply annealed glass states, for which a number of clearly defined physical properties must follow, according to theories of phase transitions. Utilizing the current machine learning techniques, we show that finite-time and finite-size analyses of the massive numerical data, produced from molecular dynamics simulations of a hard-sphere glass model, support that the Gardner transition is a second- order phase transition in three dimensions. Our study also provides estimates of the critical exponents of the transition, which traditional approaches are unable to obtain.
H. Li, Y. Jin, Y. Jiang, and J. Z. Y. Chen, Determining the nonequilibrium criticality of a Gardner transition via a hybrid study of molecular simulations and machine learning, PNAS 118, e2017392118 (2021).
K. Zhang, X. Li, Y. Jin, and Y. Jiang, Machine learning glass caging order parameters with an artificial nested neural network, Soft Matter 18, 6270--6277 (2022).