Entanglement Energetics at Zero Temperature

TL;DR

This paper demonstrates that entanglement in many-body ground states can be inferred from subsystem energy fluctuations at zero temperature, offering a practical measurement approach validated by qubit experiments.

Contribution

It introduces a novel method to quantify entanglement through energy fluctuation measurements, linking energy data to entanglement in many-body systems.

Findings

Energy fluctuations correlate with entanglement magnitude

Method applicable to qubit experiments

Provides a new entanglement quantification technique

Abstract

We show how many-body ground state entanglement information may be extracted from sub-system energy measurements at zero temperature. Generically, the larger the measured energy fluctuations are, the larger the entanglement is. Examples are given with the two-state system and the harmonic oscillator. Comparisons made with recent qubit experiments show this type of measurement provides another method to quantify entanglement with the environment.