Traces of Integrability in Relaxation of One-Dimensional Two-Mass Mixtures

TL;DR

This paper investigates how specific triplet configurations in a one-dimensional two-mass particle mixture cause anomalously slow relaxation, supported by numerical evidence and relevant for experimental optical lattice setups.

Contribution

It reveals the role of particular triplet structures in slowing relaxation in a two-mass mixture, linking integrability features to relaxation dynamics.

Findings

Identification of heavy-light-heavy triplets as slow-relaxation agents

Numerical evidence of anomalous relaxation slowdown

Potential experimental realization in optical lattice mixtures

Abstract

We study relaxation in a one-dimensional two-mass mixture of hard-core particles. A heavy-light-heavy triplet of three neighboring particles can form a little known unequal mass generalization of Newton's cradle at particular light-to-heavy mass ratios. An anomalous slow-down in the relaxation of the whole system is expected due to the presence of these triplets, and we provide numerical evidence to support this prediction. The expected experimental realization of our model involves mixtures of two internal states in optical lattices, where the ratio between effective masses can be controlled at will.