Emergent Universality Class in Dissipative Quantum Systems with Dipole Moment Conservation

TL;DR

This paper explores the universal non-equilibrium dynamics of dissipative quantum systems with dipole moment conservation, revealing a new strongly interacting fixed point and distinct transport behaviors based on dipole symmetry strength.

Contribution

It introduces an effective field theory and a quantum spin model to describe novel universality classes in dissipative quantum systems with dipole conservation.

Findings

Discovery of a new non-equilibrium fixed point.

Charge transport is subdiffusive with strong dipole symmetry.

Transport remains diffusive with weak dipole symmetry.

Abstract

Understanding the non-equilibrium dynamics of quantum many-body systems remains one of the grand challenges of modern physics. In particular, increasing attention has been devoted to the emergence of non-equilibrium universality classes that have no equilibrium counterparts. A prominent example is the Kardar-Parisi-Zhang universality class realized in dissipative Bose-Einstein condensates. In this Letter, motivated by recent experimental advances, we investigate the universal dynamics of dissipative quantum systems with dipole moment conservation. We develop an effective field theory description, supported by a concrete quantum spin model, to capture the resulting universal behaviors. Our analysis unveils a novel strongly interacting non-equilibrium fixed point that governs the equal-time phase fluctuations in systems with either strong or weak dipole symmetries. Moreover, charge transport becomes subdiffusive in the presence of strong dipole symmetry, while it remains diffusive in the weakly symmetric case. Our results reveal the intricate interplay between kinetic constraints and dissipation in quantum many-body systems.