Detecting entanglement with transport measurement in weakly interacting and fluctuating systems

TL;DR

This paper proposes a protocol to measure entanglement entropy and mutual information in complex quantum transport systems with interactions, enabling experimental quantification of entanglement in realistic many-body scenarios.

Contribution

Develops a feasible measurement protocol for von Neumann entropy and mutual information in interacting, multipartite quantum transport systems, linking these to correlation functions.

Findings

Measurement of VNE and mutual information is feasible in systems with boundary and bulk interactions.

The connection between VNE and two-point correlation functions remains valid under realistic conditions.

Mutual information can serve as an accessible indicator of system-environment entanglement.

Abstract

Measuring entanglement entropy in interacting, multipartite systems remains a significant experimental challenge. We address this challenge by developing a protocol to measure von Neumann entropy (VNE) and mutual information in quantum transport systems with both many-body interactions and multiple subsystems. Our analysis indicates that the vital connection between VNE and two-point correlation functions persists under these realistic conditions. The measurement is shown to be feasible for systems with boundary interactions and, critically, for bulk-interacting systems subject to a quantum quench of their internal couplings. Our work provides a pathway to experimentally quantify entanglement in complex interacting systems and establishes mutual information as an experimentally accessible indicator for system-environment entanglement.