Robustness of optimal transport in disordered interacting many-body networks

TL;DR

This paper investigates how the robustness of quantum transport in disordered many-body networks is affected by perturbations, symmetry properties, environment coupling, and decoherence, revealing conditions for optimal transport efficiency.

Contribution

It demonstrates that centrosymmetry enhances transport efficiency and explores how perturbations, environment coupling, and decoherence influence robustness in disordered quantum systems.

Findings

Centrosymmetry significantly improves transport efficiency.

Perturbations reduce efficiency more in optimal cases than in suboptimal ones.

Maximum efficiency occurs at finite decoherence strength in EGE, while it decreases monotonically in csEGE.

Abstract

The robustness of quantum transport under various perturbations is analyzed in disordered interacting many-body systems, which are constructed from the embedded Gaussian random matrix ensembles (EGEs). The transport efficiency can be enhanced drastically, if centrosymmetry (csEGE) is imposed. When the csEGE is perturbed with an ordinary EGE, the transport efficiency in the optimal cases is reduced significantly, while in the suboptimal cases the changes are less pronounced. Qualitatively the same behavior is observed, when parity and centrosymmetry are broken by block perturbations. Analyzing the influence of the environment coupling, optimal transport is observed at a certain coupling strength, while too weak and too strong coupling reduce the transport. Taking into account the effects of decoherence, in the EGE the transport efficiency approaches its maximum at a finite nonzero decoherence strength (environment-assisted transport). In the csEGE the efficiency decays monotonically with the decoherence but is always larger than in the EGE.