Thermodynamic Probes of Multipartite Entanglement in Strongly Interacting Quantum Systems

TL;DR

This paper introduces a thermodynamic framework using ergotropy to quantify multipartite entanglement in strongly interacting quantum systems, applicable to quantum simulators with realistic models.

Contribution

It proposes a novel method to estimate genuine multipartite entanglement via global and local ergotropy measurements, overcoming limitations of previous approaches.

Findings

Effective estimation of multipartite entanglement in various models

Applicability to noisy and shallow quantum circuits

Validation on models like Tavis-Cummings and Ising

Abstract

Quantifying multipartite entanglement in quantum many-body systems and hybrid quantum computing architectures is a fundamental yet challenging task. In recent years, thermodynamic quantities such as the maximum extractable work from an isolated system (the ergotropy) have allowed for entanglement measures that are operationally more accessible. However, these measures can be restrictive when applied to systems governed by Hamiltonians with strong collective or interparticle interactions. Motivated by advances in quantum simulators, we propose a framework that circumvents these restrictions by evaluating global and local ergotropy either through controlled quenching of interactions or by measuring suitable local observables only. We show that this formalism allows us to correctly estimate genuine multipartite entanglement in both stationary and time-evolved states of systems with strong interactions, including parametrized quantum states simulated on a quantum circuit with varying circuit depth and noise. We demonstrate its applicability to realistic physical models, namely, the Tavis-Cummings model, the three-level Dicke model, and the transverse-field Ising model, highlighting its potential as a versatile tool for characterizing entanglement in near-term quantum simulators.