Exceptional point and hysteresis trajectories in cold Rydberg atomic gases

TL;DR

This paper experimentally observes exceptional points and hysteresis trajectories in cold Rydberg atomic gases, revealing non-Hermitian dynamics caused by long-range interactions and dissipation, and providing insights into many-body non-Hermitian physics.

Contribution

It reports the first experimental observation of interaction-induced exceptional points and hysteresis in cold Rydberg gases, linking long-range interactions with non-Hermitian phenomena.

Findings

Observation of exceptional points in cold Rydberg gases

Detection of interaction-induced hysteresis trajectories

Analysis of non-Hermitian dynamics in many-body systems

Abstract

The interplay between strong long-range interactions and the coherent driving contribute to the formation of complex patterns, symmetry, and novel phases of matter in many-body systems. However, long-range interactions may induce an additional dissipation channel, resulting in non-Hermitian many-body dynamics and the emergence of exceptional points in spectrum. Here, we report experimental observation of interaction-induced exceptional points in cold Rydberg atomic gases, revealing the breaking of charge-conjugation parity symmetry. By measuring the transmission spectrum under increasing and decreasing probe intensity, the interaction-induced hysteresis trajectories are observed, which give rise to non-Hermitian dynamics. We record the area enclosed by hysteresis loops and investigate the dynamics of hysteresis loops. The reported exceptional points and hysteresis trajectories in cold Rydberg atomic gases provide valuable insights into the underlying non-Hermitian physics in many-body systems, allowing us to study the interplay between long-range interactions and non-Hermiticity.