Breaking of Time Translation Symmetry and Ergodicity, and Entropy decrease in a Continuous Time Crystal Driven by Nonreciprocal Optical Forces

TL;DR

This paper presents the first experimental analysis of transient dynamics in a light-induced time crystal, revealing symmetry breaking, ergodicity loss, and entropy decrease driven by nonreciprocal optical forces in nanowire arrays.

Contribution

It provides novel experimental insights into the transient behavior of a nonreciprocity-driven time crystal, including symmetry breaking and entropy reduction, using nanowire plasmonic metamaterials.

Findings

Breaking of continuous time translation symmetry during mobilization transition

Observation of ergodicity breaking in the system dynamics

Decrease in entropy associated with the oscillatory state

Abstract

Nonreciprocal nonequilibrium process are attracting growing interest in sociology, animal behaviour, chemistry, and nanotechnology, and may have played a role in the origin of life. It is less widely recognized, however, that in open systems light can induce nonreciprocal predator-prey like forces between nanoparticles. Such forces provide access to the continuous time crystal state of matter, which has been demonstrated in a plasmonic metamaterial array of nanowires wherein light triggers a spontaneous mobilization transition to the robust oscillatory state, breaking time translation symmetry. Here, we report on the first experimental study of the transient dynamics of light-induced mobilization and demobilization in a time crystal. By analysing time resolved phase trajectories of the system of nanowires, we show that the mobilization transition is accompanied by breaking of continuous time translation symmetry and ergodicity, and a decrease in the entropy of motion. This insight into the transient dynamics of a nonreciprocity-driven time crystal is relevant to optical timetronics, an information and communications technology paradigm relying on the unique functionalities of time crystals, and applications of the interacting nanowire oscillator platform to modelling a wide range of nonreciprocal processes from many-body dynamics to the early stages of matter-to-life transitions.