Bulletin of the American Physical Society
APS March Meeting 2022
Volume 67, Number 3
Monday–Friday, March 14–18, 2022; Chicago
Session Q21: Disordered and Glassy Systems IIRecordings Available
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Sponsoring Units: DSOFT Chair: Eric Corwin, University of Oregon Room: McCormick Place W-185D |
Wednesday, March 16, 2022 3:00PM - 3:12PM |
Q21.00001: From Crystals to Amorphous Solids Induced by Polydispersity: A Two-Step Melting-Like Transition in Three Dimensions Zhehua Jiang Starting from crystals, an evolution to amorphous solids occurs with increasing magnitude of particle-size polydispersity η, a process called amorphization transition. The nature of amorphization transition remains unsolved. We try to solve this puzzle by quasistatically increasing and then decreasing polydispersity at ηmax in three dimensions, initially from crystals, and observe two well defined transition points ηc and ηd: before ηc, all systems return to crystals with long-range translational and orientational order, after ηd, all systems transform to amorphous solids without any long-range order, and tranform into intermediate states with short-range translational order and long-range orientational order in between. We argue the analogy between amorphization transition and two-step two-dimensional melting transition. We also observe an increasing number of point defects which are the origin of the loss of long-range translational order in the intermediate states, with increasing ηmax. We argue that the point defects break the systems from order to disorder. |
Wednesday, March 16, 2022 3:12PM - 3:24PM |
Q21.00002: A mechanical model for thin sheets Madelyn J Leembruggen, Jovana Andrejevic, Arshad A Kudrolli, Christopher H Rycroft Simulations of thin sheets are a valuable tool for augmenting experimental data sets and revealing the hidden internal dynamics of the sheet’s'deformations. However, it is challenging to develop a model that performs independently of the underlying mesh topology, maps to physical parameters, and scales in a computationally efficient way. Here we employ a mechanical model for a thin sheet based on a general triangular mesh, with linear springs along edges and torsion springs between adjacent triangles. We develop a procedure for locally setting spring constants to match continuum mechanical properties. We test the model's accuracy by running simulations of instabilities in twisted elastic ribbons. We also develop an extension to the model that captures the phenomenology of plastic damage accumulation. Our simulations bridge the gap between image-based experimental data and energy-based theoretical analysis of thin sheet deformations by generating data with fine temporal and spatial resolution. |
Wednesday, March 16, 2022 3:24PM - 3:36PM |
Q21.00003: Elucidating the dynamics of crumpling via elastoplastic sheet simulation Jovana Andrejevic, Madelyn J Leembruggen, Shmuel M Rubinstein, Christopher H Rycroft Crumpled structures are often considered a model complex system in soft matter. Nevertheless, recent studies have shown that the intricate ridge network and facet size distribution of these disordered systems exhibit robust statistics. Notably, the ridge and facet size distributions that evolve over repeated axial crumpling may be effectively modeled by a physical fragmentation process. However, the task of generalizing these results for a wide range of material properties and compaction geometries remains limited by experimental data acquisition rates. To complement data-driven studies, we present a computational model of thin elastoplastic sheets that enables us to study real-time spatial damage evolution. Simulations of repeated axial crumpling demonstrate consistency with the logarithmic accumulation of total crease length observed experimentally. Moreover, we find that simulations of both axial and radial crumpling show evidence of facet size statistics as predicted by the fragmentation-based model. These observations suggest universal behavior uniting different materials and geometries of such disordered systems. |
Wednesday, March 16, 2022 3:36PM - 3:48PM |
Q21.00004: Mechanical annealing and multiple memories in an amorphous solid Nathan C Keim, Dani Medina Studies of amorphous or disordered jammed solids have shown that applying many cycles of oscillatory shear can train or anneal them, leading to a steady state with periodic particle motions. However, this process leaves an imprint of the annealing strain amplitude and of a direction of shear. In experiments with a 2D amorphous soft solid, we show that an alternative "ring-down" annealing protocol with progressively smaller amplitudes suppresses this imprint, resulting in a symmetric microstructure, and disentangling the memory of annealing from a more general behavior called return-point memory. Based on this protocol, we introduce a test of the minimum separation between multiple memories, and show that it agrees with independent measurements of the rearranging soft spots within an experimental sample. |
Wednesday, March 16, 2022 3:48PM - 4:00PM |
Q21.00005: Memory capacity and heterogeneity in swelled particle systems Hilary C Jacks Systems of particles that swell and repel store memories of the sizes to which the particles are swelled. In simulations, we investigate how system parameters such as the amount of noise, number and density of particles, interaction strength, and degree of anisotropy affect memory capacity. Additionally, we have developed a method of reading memories which relies on the distribution of nearest neighbor distances, allowing the system to remain unperturbed during reading. These statistics give us insight into which portions of these heterogeneous systems are responsible for memories. We show that individual clusters chosen from a system can be reliably used to read memories. |
Wednesday, March 16, 2022 4:00PM - 4:12PM |
Q21.00006: Path dependent versus energy dependent elements of hysteresis Varda Faghir Hagh, Chloe W Lindeman, Chi Ian Ip, Sidney R Nagel Hysterons and their interactions are often used as a simple model to study memory formation in cyclically driven materials. The default hysteron model is based on a double-well potential with two adjacent energy minima. As the system is driven periodically, it lands in one of the two available ground states solely based on its energy and the evolution of the landscape as one of the minima turns into a saddle point and disappears when the driving amplitude goes above a critical value. However, in many mechanical systems with buckling modes such as spring networks and beams, the evolution of the double-well cyclic driving is qualitatively different and the ground state in which the system finds itself depends on its pathway rather than its energy. Here we introduce a generalized hysteron model that consists of a particle connected to two harmonic, slightly compressed springs and coupled to the environment via a weak oscillatory force. We show that there is a crossover frequency below which the hysteron is path-dependent and above which the hysteron becomes energy-dependent. |
Wednesday, March 16, 2022 4:12PM - 4:24PM |
Q21.00007: Rheo-XPCS study of microstructural training and memory of nanocolloidal soft glasses through oscillatory shear Yihao Chen, Simon A Rogers, Suresh Narayanan, James L Harden, Robert L Leheny We report a study combining x-ray photon correlation spectroscopy with in situ rheology to investigate training and memory effects in soft glasses composed of bi-disperse nanocolloidal silica particles subject to periodic shear. During a training process consisting of a rectangular wave of strain, the x-ray speckle patterns undergo an evolution in which the degree of correlation in the microstructure between adjacent strain cycles steadily increases to a plateau. Simultaneously, the stress shows a steadily evolving hysteresis. The number of cycles required to reach the plateau depends approximately linearly on the scattering wave vector, indicating a process in which microscopic reversibility is reached at progressively shorter length scales during the training. Memory of the training is illustrated by applying a set of reading strain oscillations with different amplitudes to a well-trained glass. Both the degree of correlation in the microstructures and the change in stress between adjacent reading cycles vary non-monotonically with the reading amplitude, with the correlation showing a peak at the training amplitude. |
Wednesday, March 16, 2022 4:24PM - 4:36PM |
Q21.00008: Experimental signals of the Gardner transition in a quasi-thermal pressure-controlled granular glass Hongyi Xiao, Andrea J Liu, Douglas J Durian The Gardner transition in glasses is predicted to occur when metabasins in the energy landscape break up into a hierarchy of sub-basins, leading to the emergence of marginal stability. We experimentally search for signals of the Gardner transition in a quasi-thermal granular glass consisting of a monolayer of star-shaped granular particles under sub-levitating air fluidization. The pressure of the system is controlled by adjusting the tension exerted on an enclosing flexible boundary. Velocity distributions of the internal particles and the scaling of the pressure, density, effective-temperature, and relaxation time demonstrate that the system has important features of a thermal system. A pressure-based quenching protocol was developed to bring the system into deeper glassy states, and signals of the Gardner transition are detected via cage size and separation order parameters for both particle positions and orientations. This gives strong experimental evidence of the Gardner transition for a quasi-thermal system at low dimensions. |
Wednesday, March 16, 2022 4:36PM - 4:48PM |
Q21.00009: Higher Dimensional Biased Random Organization Ashley Z Guo, Sam Wilken, Dov Levine, Paul M Chaikin Random Organization (RO) and Biased Random Organization (BRO) models both exhibit dynamical phase transitions between absorbing and active states, in which active particles are displaced randomly in RO and displaced repulsively away from their overlapping neighbors in BRO. Both models have been dynamically and structurally characterized in detail in both 2D and 3D. RO in each case exhibits Manna universality class behavior; previous work has shown that 3D BRO remains Manna class, and approaches a random close packed (RCP) structure at a critical endpoint, while 2D BRO exhibits Manna behavior only above a certain displacement size and instead approaches a crystalline phase as displacement size approaches zero. Here, we extend the study of RO and BRO to higher dimensions and compare their behavior in 4D (the upper critical dimension for Manna class), including their critical exponents and hyperuniformity. Furthermore, we show that 4D BRO approaches the 4D RCP density calculated previously in literature. |
Wednesday, March 16, 2022 4:48PM - 5:00PM |
Q21.00010: Sound attenuation in low temperature amorphous solids is primarily determined by non-affine displacements Grzegorz Szamel, Elijah J Flenner We analyze sound attenuation in low temperature classical amorphous solids. Starting from the microscopic equations of motion we derive an exact expression for the zero-temperature sound damping coefficient. We use computer simulations of glasses of widely varying stability to verify that the sound damping coefficients calculated from our expression agree with results from direct simulations of sound damping. To get some physical understanding of the content and the meaning of our expression we analyze it in the limit of small wavevectors. We find 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. Our approach can be used to evaluate the low temperature sound damping coefficients without directly simulating sound attenuation. |
Wednesday, March 16, 2022 5:00PM - 5:12PM |
Q21.00011: Mean-field model for the Curie-Weiss temperature dependence of coherence length in metallic liquids Charles K Lieou, Takeshi Egami The coherence length of metallic liquids, which determines viscosity, is known to display a Curie-Weiss temperature dependence; when extrapolated from temperatures above the glass transition, the coherence length diverges at a negative temperature with a critical exponent of unity. We propose a mean-field pseudospin model that explains this behavior. Specifically, we model the atoms and their local environment as Ising spins with antiferromagnetic exchange interactions. We further superimpose an exchange interaction between clusters of atoms, or dynamical heterogeneities, which are soft spots susceptible to atomic rearrangement, whose typical size is determined by the atomic correlation length. The coherence length in the metallic liquid is thus the correlation length between dynamical heterogeneities. Our results reaffirm the idea that the coherence length is a measure of point-to-set correlations, and that local frustrations in the interatomic interactions are prominent in coherence in metallic liquids. |
Wednesday, March 16, 2022 5:12PM - 5:24PM Withdrawn |
Q21.00012: Scaling for disordered viscoelastic matter at the onset of rigidity: Dynamical susceptibility,global behavior and spatio-temporal properties Danilo B Liarte, Stephen J Thornton, Eric M Schwen, Itai Cohen, Debanjan Chowdhury, James P Sethna The onset of rigidity in interacting liquids, as they undergo a transition to a disordered solid, is associated with a dramatic rearrangement of the low-frequency vibrational spectrum. In this talk, I will derive scaling forms for the singular dynamical response of disordered viscoelastic networks near both jamming and rigidity percolation. Using effective-medium theory, I will extract critical exponents, invariant scaling combinations and analytical formulas for universal scaling functions near these transitions. Our scaling forms describe the behavior in space and time near the various onsets of rigidity, for rigid and floppy phases and the crossover region, including diverging length and time scales at the transitions. We expect that these behaviors can be measured in systems ranging from colloidal suspensions to anomalous charge-density fluctuations of "strange" metals. |
Wednesday, March 16, 2022 5:24PM - 5:36PM |
Q21.00013: Propensity sImulations with polydisperse particles in advance of experimental propensity measurements. Cordell J Donofrio We present our findings from our recently published work on simulations of the Kob-Andersen binary glassformer in a series of isoconfigurational (IC) ensembles. This follows the work of Widmer-Cooper et al, (2004), where they used such an ensemble to define the propensity of each particle as the average motion of the particle, where the averaging is done across the ensemble. Our focus was on introducing polydispersity to the particle sizes in anticipation of creating IC ensembles with a binary mixture of silica particles. Our simulations indicated that meaningful measurements of propensity should be possible when each component of a binary mixture has commercially available levels of polydispersity. However, we also found that care must be taken in constructing each member of the IC ensemble as particles could not be considered indistinguishable due to the size variation within each of the binary species. We will also share our work to date on creating such an ensemble using a holographic optical tweezer system. |
Wednesday, March 16, 2022 5:36PM - 5:48PM |
Q21.00014: Fragile to strong crossover in a model glass-former Srikanth Sastry, Pallabi Das Glass-forming liquids are broadly classified fragile and strong glass-forming liquids, which show non-Arrhenius and Arrhenius temperature dependence of dynamics, respectively, as the glass transition temperature is approached. In liquids like water or silica, a fragile to strong crossover is observed at lower temperatures. Though, most metallic glass-formers show fragile behaviour for a wide range of temperatures, it has recently been found that even metallic glass-forming liquids show a fragile to strong crossover in dynamics when really low temperatures are accessed. In our work, we have computationally studied the Kob-Andersen model for a wide range of temperatures and have accessed really low temperatures below the mode coupling temperature(TMCT). We find signatures of a possible fragile to strong dynamical crossover below TMCT consistent with the previous findings in different metallic glass formers. We investigate aspects of dynamical heterogeneity and thermodynamics accompanying this crossover. |
Wednesday, March 16, 2022 5:48PM - 6:00PM |
Q21.00015: Marginal Stability of Soft Anharmonic Mean Field Spin Glasses Giampaolo Folena, Pierfrancesco Urbani Crystalline solids can be understood in terms of their lattice symmetries which control, at low energies their phononic spectrum. Conversely, what happens with disordered solids such as glasses is very much not well understood. Such amorphous systems present a gapless spectrum of harmonic excitations together with an abundance of non-linear excitations giving rise to avalanches and two-level systems. We discuss the solution of the glass phase of a mean-field model, recently introduced, and show that it is marginally stable by means of two different mechanisms: soft linear excitations —appearing in a gapless spectrum of the Hessian of the energy landscape— and pseudogapped non-linear excitations —corresponding to nearly degenerate two level systems (TLS). In this model TLS appear in a dynamical way and are the result of interactions between degrees of freedom.
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