Multimode dynamics and emergence of a characteristic length-scale in a one-dimensional quantum system

TL;DR

This paper investigates the non-equilibrium dynamics of a split 1D Bose gas, revealing two distinct relaxation regimes and identifying a crossover length-scale linked to prethermalization, thus providing insights into multimode quantum dynamics.

Contribution

It introduces a method to directly observe multimode dynamics and characterizes the length-scale dependent relaxation regimes in a 1D quantum system.

Findings

Identification of two distinct relaxation regimes

Measurement of the crossover length-scale

Observation of prethermalized phase-correlation length

Abstract

We study the non-equilibrium dynamics of a coherently split one-dimensional (1d) Bose gas by measuring the full probability distribution functions of matter-wave interference. Observing the system on different length scales allows us to probe the dynamics of excitations on different energy scales, revealing two distinct length-scale dependent regimes of relaxation. We measure the crossover length-scale separating these two regimes and identify it with the prethermalized phase-correlation length of the system. Our approach enables a direct observation of the multimode dynamics characterizing one-dimensional quantum systems.