Observation of scaling in the dynamics of a strongly quenched quantum gas

TL;DR

This paper reports the experimental observation of universal scaling behavior in the dynamics of a strongly quenched two-component Bose gas near a quantum critical point, highlighting a new approach to studying quantum critical phenomena.

Contribution

It demonstrates the first experimental observation of scaling in the time evolution of a quantum gas after a quench near a critical point, linking dynamics to universality classes.

Findings

Scaling behavior observed in post-quench dynamics

Crossover phenomena reminiscent of finite-temperature criticality

Provides a new method to probe quantum critical properties

Abstract

We report on the experimental observation of scaling in the time evolution following a sudden quench into the vicinity of a quantum critical point. The experimental system, a two-component Bose gas with coherent exchange between the constituents, allows for the necessary high level of control of parameters as well as the access to time-resolved spatial correlation functions. The theoretical analysis reveals that when quenching the system close to the critical point, the energy introduced by the quench leads to a short-time evolution exhibiting crossover reminiscent of the finite-temperature critical properties in the system's universality class. Observing the time evolution after a quench represents a paradigm shift in accessing and probing experimentally universal properties close to a quantum critical point and allows in a new way benchmarking of quantum many-body theory with experiments.