Atharva Shukla | Searcharxiv

arXiv2025

Dynamics of self-organization in dense persistent active matter

We consider a two-dimensional athermal binary mixture of Lennard-Jones particles with persistent random active forces. The liquid phase of this system for active forces exceeding a threshold value exhibits self-organization with long-range spatial correlations of particle velocities and active forces. We study by simulations the development of these correlations from a random initial state. Several characteristics of the growth of correlations are measured and compared with those of phase-ordering kinetics of equilibrium systems after a quench from a disordered state. The motion of the particles in the long-time steady state is found to be dominated by two streams that flow in opposite directions.

cond-mat.soft↗

arXiv2023

Superposing compass states for asymptotic isotropic sub-Planck phase-space sensitivity

Compass states deliver sub-Planck phase-space structure in the sense that sensitivity to phase-space displacement is superior to the sensitivity of displacing the vacuum state in any direction, but this sensitivity is anisotropic: better sensitivity for some directions of phase-space displacement vs others. Here we introduce generalised compass states as superpositions of $n$ compass states, with each oriented by $\fracπ{2n}$ with respect to its predecessor. Specifically, we derive Wigner functions for these generalised compass states and approximate closed-form expressions for overlaps between generalised compass states and their displaced counterparts. Furthermore, we show that generalised compass states, in the limit $n\to\infty$, display isotropic sensitivity to phase-space displacement in any direction.

quant-ph↗