Steady state entanglement beyond thermal limits

TL;DR

This paper demonstrates that driven-dissipative quantum systems can generate entanglement beyond classical thermal limits, with maximal entanglement occurring under highly irreversible conditions and negative effective temperatures.

Contribution

It introduces a framework to analyze entanglement generation as a continuous quantum machine, revealing that irreversibility enhances entanglement beyond thermal bounds.

Findings

Maximal concurrence occurs at negative effective temperatures.

Irreversibility correlates with increased entanglement.

Entanglement surpasses classical thermal limits.

Abstract

Classical engines turn thermal resources into work, which is maximized for reversible operations. The quantum realm has expanded the range of useful operations beyond energy conversion, and incoherent resources beyond thermal reservoirs. This is the case of entanglement generation in a driven-dissipative protocol, which we hereby analyze as a continuous quantum machine. We show that for such machines the more irreversible the process the larger the concurrence. Maximal concurrence and entropy production are reached for the hot reservoir being at negative effective temperature, beating the limits set by classic thermal operations on an equivalent system.