Work Extraction and Energy Storage in the Dicke Model

TL;DR

This paper investigates work extraction and energy storage in the Dicke model, revealing that highly entangled states may be inefficient for energy storage when considering initial state preparation costs, despite the model's criticality benefits.

Contribution

It demonstrates that entanglement is not always advantageous for energy storage in quantum many-body systems, especially under non-optimal protocols and initial state costs.

Findings

Entangled states can be inefficient for energy storage considering preparation costs.

Criticality can enhance work extraction despite entanglement inefficiencies.

Non-optimal processes influence the role of entanglement in quantum thermodynamics.

Abstract

We study work extraction from the Dicke model achieved using simple unitary cyclic transformations keeping into account both a non optimal unitary protocol, and the energetic cost of creating the initial state. By analyzing the role of entanglement, we find that highly entangled states can be inefficient for energy storage when considering the energetic cost of creating the state. Such surprising result holds notwithstanding the fact that the criticality of the model at hand can sensibly improve the extraction of work. While showing the advantages of using a many-body system for work extraction, our results demonstrate that entanglement is not necessarily advantageous for energy storage purposes, when non optimal processes are considered. Our work shows the importance of better understanding the complex interconnections between non-equilibrium thermodynamics of quantum systems and correlations among their subparts.