# Dissipation Induced Structural Instability and Chiral Dynamics in a Quantum Gas

## TL;DR

This paper reports the discovery of a non-stationary, chiral state in a spinor Bose gas system where controlled dissipative and unitary interactions induce a novel dynamical instability, revealing new insights into many-body quantum dynamics.

## Contribution

The study introduces a synthetic many-body system with independently tunable dissipative and unitary couplings, demonstrating a chiral dynamical state driven by dissipation.

## Key findings

- Observation of chiral evolution in a Bose-Einstein condensate
- Mapping of the chiral dynamics to a positional instability
- Controlled dissipation induces non-stationary states in quantum gases

## Abstract

Dissipative and unitary processes define the evolution of a many-body system. Their interplay gives rise to dynamical phase transitions and can lead to instabilities. We discovered a non-stationary state of chiral nature in a synthetic many-body system with independently controllable unitary and dissipative couplings. Our experiment is based on a spinor Bose gas interacting with an optical resonator. Orthogonal quadratures of the resonator field coherently couple the Bose-Einstein condensate to two different atomic spatial modes whereas the dispersive effect of the resonator losses mediates a dissipative coupling between these modes. In a regime of dominant dissipative coupling we observe the chiral evolution and map it to a positional instability.