Prethermalization Revealed by the Relaxation Dynamics of Full Distribution Functions

TL;DR

This paper experimentally investigates prethermalization in a one-dimensional Bose gas, showing that the system rapidly reaches a quasi-steady state characterized by an effective temperature, before eventual thermalization.

Contribution

It provides the first detailed experimental analysis of prethermalization dynamics using full quantum distribution functions in a 1D Bose gas.

Findings

System evolves towards a quasi-steady state with an effective temperature.

Prethermalization occurs before full thermalization.

Comparison with the Tomonaga-Luttinger model confirms non-thermal steady state.

Abstract

We detail the experimental observation of the non-equilibrium many-body phenomenon prethermalization. We study the dynamics of a rapidly and coherently split one-dimensional Bose gas. An analysis based on the use of full quantum mechanical probability distributions of matter wave interference contrast reveals that the system evolves towards a quasi-steady state. This state, which can be characterized by an effective temperature, is not the final thermal equilibrium state. We compare the evolution of the system to an integrable Tomonaga-Luttinger liquid model and show that the system dephases to a prethermalized state rather than undergoing thermalization towards a final thermal equilibrium state.