Vinay VAIBHAV

Postdoctoral Researcher in Theoretical & Computational Soft Matter Physics

Georg-August-Universität Göttingen | Institut für Theoretische Physik

Vinay Vaibhav profile photo Animation of active amorphous solids simulation

Research

I study the physics of soft and disordered materials—glassy liquids, amorphous solids, polymers, and dense active matter—using large-scale simulations and theory, often in close collaboration with experiments. Across these areas, I am interested in how disorder, activity, and external driving shape structure, dynamics, and mechanical response in complex materials.

Dense Active Matter: Jamming, Fluidization, Avalanches

I examine how dense active materials—made of self-propelled particles—switch between jammed, solid-like states and flowing, fluidized states. In athermal active glasses [1–3], I probe how self-propulsion destabilizes stable amorphous solids, how thermal or processing history sets the activity threshold for fluidization, and how collective rearrangements and avalanches emerge near this transition. A key goal is to connect activity-induced fluidization with yielding in passive amorphous solids, especially through shared signatures of dynamic heterogeneity.

Related publications:

  1. Jamming-to-Fluidization Transition in Dense Athermal Active Matter (in preparation, 2026).
  2. Avalanches in Dense Active Matter (in preparation, 2026).
  3. Dynamic Heterogeneity in Active Liquids (in preparation, 2026).

Polymer Viscoelasticity from Non-affine Lattice Dynamics

With experimental and industrial partners, I link atomistic polymer structure to macroscopic mechanical response. Using non-affine lattice dynamics [1–3], we predict viscosity and viscoelastic moduli across many decades in frequency—from fast molecular vibrations to slow mechanical tests. This scale-bridging framework lets us interpret data on epoxy resins and glassy polymers directly in terms of microscopic structure and relaxation.

Related publications:

  1. V. Vaibhav, T. W. Sirk, and A. Zaccone, Macromolecules 57, 10885 (2024).
  2. A. Singh, V. Vaibhav, T. W. Sirk, and A. Zaccone, J. Chem. Phys. 162, 244504 (2025).
  3. A. Singh, V. Vaibhav, et al., Atomistic Framework for Glassy Polymer Viscoelasticity Across Twenty Frequency Decades, arXiv:2511.18406 (2026).
Polymer viscoelastic moduli across frequency decades via NALD

Figure 3: Scale-bridging non-affine lattice dynamics (NALD) predicting storage ($G'$) and loss ($G''$) moduli across 20 frequency decades.

Thermal Response of Glassy Systems

I study how glasses respond to temperature gradients and local heating, with implications for transport and processing. In a binary Lennard-Jones glass [1], I showed that heat and mass transport decouple near the glass transition, driving strong composition gradients (Soret effect) and nonlinear thermal responses. In ultrastable polydisperse glasses [2], I investigate how local heating nucleates a melting front, when melting proceeds via a propagating interface versus homogeneous melting, and what controls front dynamics.

Related publications:

  1. V. Vaibhav, J. Horbach, and P. Chaudhuri, Phys. Rev. E 101, 022605 (2020).
  2. V. Vaibhav, J. Horbach, and P. Chaudhuri, Front Propagation During Melting of Glass via Local Heating (in preparation, 2026).
Soret effect and local heating response in glasses

Figure 1: Thermal response and Soret coefficient $S_T$ behavior in supercooled glass-forming mixtures under thermal gradients.

Rheology and Failure of Glassy and Complex Liquids

I analyze how amorphous solids and complex liquids deform, flow, and fail. In size-polydisperse mixtures [1], I identified a rigid network of large particles coexisting with mobile small particles, and showed how this dynamic partitioning shapes bulk rheology. In confined Poiseuille flow [2], I clarified how stress gradients, boundaries, and thermalization alter local flow relative to bulk behavior. Recent work engineers controlled spatial inhomogeneities in glasses [3] to direct shear bands and failure pathways, linking microscopic stability contrasts to macroscopic failure.

Related publications:

  1. V. Vaibhav and P. Chaudhuri, Phys. Fluids 33, 053103 (2021).
  2. V. Vaibhav, J. Horbach, and P. Chaudhuri, Soft Matter 18, 4427–4436 (2022).
  3. V. Vaibhav, J. Horbach, and P. Chaudhuri, Phys. Rev. Materials 7, 095601 (2023).
Shear deformation, Poiseuille flow, and shear banding

Figure 2: Microscopic boundary deformation, non-uniform velocity/stress profiles in Poiseuille flow, and emergent shear-banding failure pathways.

Supercooled Glassy Liquids and Dynamic Heterogeneity

I study how dynamics slow and become heterogeneous near the glass transition, and how this depends on interactions, density, and temperature. In disparate-size mixtures [1], I showed that apparent transport of slow particles can be dominated by collective motion, and that removing center-of-mass drift reveals the true localization and glassy signatures. With collaborators [2–3], I use information-theoretic measures (negentropy) of displacement distributions to define entropic timescales of dynamic heterogeneity and to analyze “Brownian yet non-Gaussian” diffusion. In inverse-power-law glass-formers [4], I explore density–temperature scaling and crossover temperatures that unify thermodynamics and dynamics across densities.

Related publications:

  1. V. Vaibhav, J. Horbach, and P. Chaudhuri, J. Chem. Phys. 156, 244501 (2022).
  2. V. Vaibhav and S. Dutta, Phys. Rev. E 109, L062102 (2024).
  3. V. Vaibhav, T. Das, and S. Dutta, Annalen der Physik 538 (4), e00247 (2026).
  4. A. Singh, V. Vaibhav, S. L. Singh, and Y. Singh, Glassy Dynamics, Crossover Temperature and Density Scaling in Fragile Glass-formers (ongoing).
Mean squared displacement and self-intermediate scattering function tails

Figure 4: Intermittent particle transport and non-Gaussian displacement distributions $G_s(x,t)$ in supercooled liquids.