Does Entanglement Correlation in Ground State Guarantee Quantum Energy Teleportation?

TL;DR

This paper investigates whether entanglement in the ground state guarantees successful quantum energy teleportation, revealing that in the Toric Code model, entanglement does not necessarily enable QET.

Contribution

The study challenges the common assumption that entanglement correlation in ground states always facilitates QET, using the Toric Code as a counterexample.

Findings

Entanglement in the Toric Code ground state does not guarantee QET success.

PVM measurements show no LOCC can achieve QET in the Toric Code.

Entanglement alone may not be sufficient resource for QET in certain models.

Abstract

Although extraction of energy from the ground state is forbidden, one can utilize Quantum Energy Teleportation (QET) protocol for energy extraction -- a two-step protocol involving quantum measurements followed by LOCC. This is an unique method to ``extract energy from ground states'' of quantum systems. QET requires some correlation in the ground state, and entanglement correlation plays a crucial roles as a resource. The general belief is that if the ground state is quantum-correlated via entanglement for two different sites in a quantum system, and if we perform measurements on one of the sites, we can find an LOCC for the other site to successfully accomplish QET. In this paper, we show that this belief may not be true in the case of the Toric Code. We demonstrate this by performing a PVM measurements on spins in the Toric Code. Based on the measurement outcomes, we found that there is no LOCC for successful QET.