Impact of Dissipation on Universal Fluctuation Dynamics in Open Quantum Systems

TL;DR

This paper investigates how dissipation affects universal fluctuation dynamics in open quantum systems, revealing that certain types of dissipation alter the universality class of surface-roughness growth, while others destroy universal behavior.

Contribution

It provides a theoretical analysis using exact numerical and renormalization-group methods to show how different dissipation mechanisms modify universal fluctuation dynamics in quantum systems.

Findings

Dephasing changes surface-roughness dynamics to Edwards-Wilkinson class.

Particle loss and gain break the universality of fluctuation dynamics.

Dissipation can either alter or destroy universal fluctuation behavior.

Abstract

Recent experimental and theoretical works have uncovered nontrivial quantum dynamics due to external dissipation. Using an exact numerical method and a renormalization-group-based analytical technique, we theoretically elucidate that dissipation drastically alters universal particle-number-fluctuation dynamics related to surface-roughness growth in non-interacting fermions and bosons. In a system under dephasing that causes loss of spatial coherence, we find that a universality class of surface-roughness dynamics changes from the ballistic class to a class with the Edwards-Wilkinson scaling exponents and an unconventional scaling function. On the other hand, in a system under dissipation with in- and out-flow of particles that breaks particle-number conservation, the universal dynamics is lost.