Disorder-robust entanglement transport

TL;DR

This paper investigates how disorder affects entangled particle transport in topological insulators, revealing symmetry-protected robustness of relative states versus sensitivity of center-of-mass states, with implications for quantum interferometry.

Contribution

It provides a platform-independent analysis of disorder effects on entangled particles, highlighting symmetry-based protection mechanisms for certain states.

Findings

Relative entangled states are protected by mirror symmetry against disorder.

Center-of-mass states remain sensitive to disorder, affecting entanglement detection.

Disorder-averaged quantum master equations effectively describe the system's behavior.

Abstract

We study the disorder-perturbed transport of two entangled particles in the absence of backscattering. This situation is, for instance, realized along edges of topological insulators. We find profoundly different responses to disorder-induced dephasing for the center-of-mass and relative coordinates: While a mirror symmetry protects even highly delocalized relative states when resonant with the symmetry condition, delocalizations in the center of mass (e.g. two-particle N00N states) remain fully sensitive to disorder. We demonstrate the relevance of these differences to the example of interferometric entanglement detection. Our platform-independent analysis is based on the treatment of disorder-averaged quantum systems with quantum master equations.