Article
Chemistry, Physical
Alejandro R. R. Verde, Laureano M. M. Alarcon, Gustavo A. A. Appignanesi
Summary: A salient feature of supercooled liquids is the dramatic dynamical slowdown as temperature decreases without significant structural change. These liquids also exhibit dynamical heterogeneities, where certain molecules relax much faster than others. However, there is no strong direct correlation between static quantities and the fast-moving molecules.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Ceramics
Danqi Yin, Kuo-Hao Lee, Collin J. Wilkinson, Yongjian Yang, Karan Doss, John C. Mauro
Summary: Dynamical heterogeneities in glass-forming systems result in spatiotemporal fluctuations and a wide distribution of relaxation rates. This study investigates the dominant factors governing dynamical heterogeneities in borosilicate glass. Molecular dynamics simulations using the isoconfigurational ensemble method were performed to study the dynamical heterogeneities of two alkali-(alumino)borosilicate glasses. It was found that alkali ions exhibit high dynamical propensities in local spatial regions. The number of bridging oxygens for boron and silicon does not monotonically correlate with their corresponding dynamical propensities.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Chemistry, Physical
Hayato Shiba, Masatoshi Hanai, Toyotaro Suzumura, Takashi Shimokawabe, Takashi Shimokawabe
Summary: Recent developments in machine learning have made accurate predictions of the dynamics of slow structural relaxation in glass-forming systems possible. However, existing machine-learning models mainly focus on learning a single dynamic quantity and its relation to the structural features of glassy liquids. In this study, a graph neural network model called "BOnd TArgeting Network (BOTAN)" is proposed, which learns the relative motion between neighboring pairs of particles and the self-motion of particles. By relating the structural features to these two different dynamical variables, the model can autonomously discern the effects of different dynamical processes on the self-motion of particles undergoing slow relaxation, thus enabling high-precision prediction of slow structural relaxation in space and time.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Mechanics
David Machado, Roberto Mulet, Federico Ricci-Tersenghi
Summary: In this study, we investigate the stochastic relaxation dynamics of the Ising p-spin model on a random graph. We introduce a new closure scheme for the master equation and propose a solution to the problem of short relaxation timescale in the low-temperature regime. The results are in good agreement with extensive Monte Carlo simulations.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2023)
Article
Physics, Fluids & Plasmas
Siavash Soltani, Chad W. Sinclair, Joerg Rottler
Summary: Using machine learning techniques, we have developed a Markov state model (MSM) to investigate the structural heterogeneities and slow dynamics of a model glass former. By coarse-graining the molecular dynamics into a low-dimensional feature space, we are able to reveal important aspects of the system's behavior. Our results show that the transition timescale between states is longer than the conventional structural relaxation time, but can still be obtained from shorter trajectories. The identified states in our model correspond to local excess Voronoi volume, highlighting packing fluctuations as a dominant factor in the slow relaxation of the system.
Article
Physics, Multidisciplinary
Yanshuang Chen, Zefang Ye, Kexin Wang, Jiping Huang, Hua Tong, Yuliang Jin, Ke Chen, Hajime Tanaka, Peng Tan
Summary: Glasses can relax internally even when their structure is frozen. In a two-dimensional glass former, non-constrained bonds survive the freezing of structural relaxation, leading to persistent internal relaxation. This study directly visualizes the internal relaxations in a glass through observations of a mechanically driven granular system, revealing the emergence of slow beta relaxation as the structure relaxation freezes.
Article
Chemistry, Physical
Daniele Coslovich, Robert L. Jack, Joris Paret
Summary: This study uses unsupervised learning methods to characterize the disordered microscopic structure of supercooled liquids and glasses. Dimensionality reduction is performed on smooth structural descriptors, and the ability of the method to capture the essential structural features of glassy binary mixtures is assessed. The results indicate that some mixtures have well-defined locally favored structures and are reflected in bimodal distributions of structural variables identified through dimensionality reduction.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Kumpei Shiraishi, Hideyuki Mizuno, Atsushi Ikeda
Summary: Supercooled liquids with complicated structural relaxation processes have been a long-standing problem in condensed matter physics. Previous experiments observed that relaxation dynamics in many molecular liquids separate into two distinct processes at low temperatures. This study uses molecular dynamics simulations to investigate the potential energy landscape and provides the first direct evidence of the topographic hierarchy that induces relaxation. The results contribute to a fundamental and comprehensive understanding of relaxation dynamics in supercooled liquids.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Multidisciplinary
Bichitra Borah, Gobin Raj Acharya, Diana Grajeda, Matthew S. Emerson, Matthew A. Harris, Am Milinda Abeykoon, Joshua Sangoro, Gary A. Baker, Andrew J. Nieuwkoop, Claudio J. Margulis
Summary: This article reports on the structural-dynamic pathway from liquid to glass in ionic liquids containing a specific cation. Experimental and computational evidence suggests that the transition from liquid to glass occurs in separate stages.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Physics, Multidisciplinary
Stefan Boettcher, Paula A. Gago, Paolo Sibani
Summary: Research shows that restricting the impact of energy fluctuations on records is crucial for the evolution of systems during glassy relaxation.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2022)
Article
Multidisciplinary Sciences
Jianhua Zhang, Wen Zheng, Shiyun Zhang, Ding Xu, Yunhuan Nie, Zhehua Jiang, Ning Xu
Summary: This study explores the definition of temperature for nonequilibrium systems, focusing on fluctuation-dissipation temperatures and proposing that they represent characteristic temperatures of their equilibrium counterparts. By calculating the fluctuation-dissipation relation of inherent structures, a temperature-like quantity T-IS is obtained, which matches with crystallization temperature T-c for crystal-formers and onset temperature T-on for glass-formers. The research reveals the nature of effective temperatures, the connections between nonequilibrium and equilibrium systems, and confirms the equivalence between T-on and T-c.
Article
Chemistry, Physical
A. Mansuri, P. Muenzner, T. Feuerbach, A. W. P. Vermeer, W. Hoheisel, R. Boehmer, M. Thommes, C. Gainaru
Summary: This study investigates the molecular dynamics of imidacloprid using dielectric spectroscopy, oscillatory shear rheology, and calorimetry, revealing that the molecular dynamics in its glassy state strongly depends on its thermal history. The research shows that different methods predict different relaxation times, indicating the complexity of imidacloprid's behavior in technological applications.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Joerg Schnauss, Tom Kunschmann, Steffen Grosser, Paul Mollenkopf, Tobias Zech, Jessica S. Freitag, Dusan Prascevic, Roland Stange, Luisa S. Roettger, Susanne Roenicke, David M. Smith, Thomas M. Bayerl, Josef A. Kaes
Summary: The addition of heavy water under solvent conditions can significantly slow down cellular movement, increase intracellular viscosity, and lead to a reversible gelation of the cytoplasm. These changes affect cellular dynamics and can impair cell movement, with effects that are fully reversible.
ADVANCED MATERIALS
(2021)
Article
Physics, Fluids & Plasmas
Hai-Rong Qin, Chun-Shing Lee, Yong-Jun Lu
Summary: This article proposes a distinguishable-particle glassy model suitable for molecular dynamics simulation of structural glasses. The kinetic fragility of supercooled liquids can be sensitively tuned by changing the distribution of particle interactions. Liquid-liquid phase transitions are observed above the glass transition in the model liquid, and these transitions are facilitated by lowering fragility.
Article
Physics, Multidisciplinary
Vincent E. Debets, Hartmut Loewen, Liesbeth M. C. Janssen
Summary: Chiral active matter has attracted increasing interest due to the rich asymmetries that can be achieved in active particles. However, the study of chiral active glasses, as opposed to chiral crystals, has been largely unexplored. This study demonstrates that when chiral fluids are pushed to glassy conditions, they exhibit highly nontrivial dynamics, especially compared to standard linear active fluids. The introduction of a hammering mechanism, unique to rapidly spinning particles in high-density conditions, can fluidize a chiral active solid.
PHYSICAL REVIEW LETTERS
(2023)
Article
Mechanics
Grzegorz Szamel
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2019)
Article
Physics, Multidisciplinary
Grzegorz Szamel, Elijah Flenner
Summary: Model systems of self-propelled particles replicate phenomena observed in laboratory active matter systems that challenge our thermal equilibrium-based intuition. Studies have shown that different particles in self-propelled systems exhibit non-trivial equal-time correlations, which are absent in equilibrium systems. Furthermore, researchers have found that the range of velocity correlations increases with increasing persistence time of self-propulsion.
Article
Chemistry, Physical
Alireza Shakerpoor, Elijah Flenner, Grzegorz Szamel
Summary: Researchers derived a distribution function for the position of a tagged active particle in a system of interacting active particles, revealing a new effective temperature that is determined by the ratio of self-diffusion and tagged particle mobility coefficients.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Grzegorz Szamel
Summary: In this study, an alternative theory for the relaxation of density fluctuations in glass-forming fluids is proposed. By deriving a local-in-time equation of motion for the density correlation function, the significance of the Franz-Parisi free energy functional for the evolution of the density correlation function is identified.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Grzegorz Szamel, Elijah Flenner
Summary: In this study, we analyze sound attenuation starting directly from the microscopic equations of motion and derive an exact expression for the zero-temperature sound damping coefficient. We verify that the sound damping coefficients calculated from our expression agree very well with results from independent simulations of sound attenuation. Small wavevector analysis shows that sound attenuation is primarily determined by the non-affine displacements' contribution to the sound wave propagation coefficient coming from the frequency shell of the sound wave.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Lijin Wang, Grzegorz Szamel, Elijah Flenner
Summary: The density of states for two-dimensional glasses exhibits different system-size scaling depending on the number of particles. For systems with fewer than 100 particles, the density of states scales with the system size as if all the modes were plane-wave-like. However, for systems with more than 100 particles, the cumulative density of states below the first transverse sound mode frequency shows a different system-size dependence, suggesting quasi-localized modes. In addition, the cumulative density of states scales with the frequency as a power law with an exponent that leads to β = 3.5 for the density of states.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Grzegorz Szamel
Summary: This passage discusses the elastic constants of zero-temperature amorphous solids, which are calculated by subtracting a correction term from the Born term. The correction term represents the nonaffine deformation of the solid at the microscopic level. The derived alternative expressions for the elastic constants are non-negative and can be used in approximate theories for sound damping and elastic constants in zero-temperature amorphous solids.
Article
Physics, Fluids & Plasmas
Grzegorz Szamel
Summary: The interest in active matter stimulates the need to generalize thermodynamic description and relations to active matter systems. One important example is the Jarzynski relation, which is not generally valid for processes connecting stationary states of active matter systems, as shown using a simple model system.
Article
Physics, Fluids & Plasmas
Chen Liu, Giulio Biroli, David R. Reichman, Grzegorz Szamel
Summary: This paper analytically derives the exact closed dynamical equations for liquids with short-ranged interactions in large spatial dimensions using statistical mechanics tools. It simplifies the path-integral-based route to these equations and provides insight into high-dimensional liquids and glass formation. The construction also offers a means to analyze related dynamical problems accurately and devise cluster generalizations of the exact solution in infinite dimensions, opening the door to constructing increasingly accurate theories of vitrification in three-dimensional liquids.
Article
Physics, Fluids & Plasmas
Giulio Biroli, Patrick Charbonneau, Eric Corwin, Yi Hu, Harukuni Ikeda, Grzegorz Szamel, Francesco Zamponi
Summary: The random Lorentz gas (RLG) is a minimal model that demonstrates continuous localization transition in heterogeneous media and is also used to describe the discontinuous dynamical transition of glasses. In high-dimensional space, the caging transition in RLG precedes and prevents the percolation transition, while activated processes can destroy the glass transition in finite dimensions.
Article
Physics, Fluids & Plasmas
Grzegorz Szamel
Article
Physics, Fluids & Plasmas
Elijah Flenner, Grzegorz Szamel
Article
Chemistry, Physical
Lijin Wang, Grzegorz Szamel, Elijah Flenner
Article
Chemistry, Physical
Elijah Flenner, Lijin Wang, Grzegorz Szamel
Article
Chemistry, Physical
Alireza Shakerpoor, Elijah Flenner, Grzegorz Szamel
