Ergotropy and entanglement in critical spin chains
Quantum Physics
2023-03-28 v2 Statistical Mechanics
Abstract
A subsystem of an entangled ground state is in a mixed state. Thus, if we isolate this subsystem from its surroundings we may be able to extract work applying unitary transformations, up to a maximal amount which is called ergotropy. Once this work has been extracted, the subsystem will still contain some bound energy above its local ground state, which can provide valuable information about the entanglement structure. We show that the bound energy for half a free fermionic chain decays as the square of the entanglement entropy divided by the chain length, thus approaching zero for large system sizes, and we conjecture that this relation holds for all 1D critical states.
Cite
@article{arxiv.2207.13998,
title = {Ergotropy and entanglement in critical spin chains},
author = {Begoña Mula and Eva M. Fernández and José E. Alvarellos and Julio J. Fernández and David García-Aldea and Silvia N. Santalla and Javier Rodríguez-Laguna},
journal= {arXiv preprint arXiv:2207.13998},
year = {2023}
}