FiniteTime Optimization of Quantum Szilard heat engine
Abstract
We propose a finitetime quantum Szilard engine (QSE) with a quantum particle with spin as the working substance (WS) to accelerate the operation of information engines. We introduce a Maxwell's demon (MD) to probe the spin state within a finite measurement time $t_{\rm M}$ to capture the whichway information of the particle, quantified by the mutual information $I(t_{\rm{M}})$ between WS and MD. We establish that the efficiency $\eta$ of QSE is bounded by $\eta\leq1(1\eta_{\rm{C}}){\rm ln}2/I(t_{\rm M})$, where $I(t_{\rm M})/\rm{ln}2$ characterizes the ideality of quantum measurement, and approaches $1$ for the Carnot efficiency reached under ideal measurement in quasistatic regime. We find that the power of QSE scales as $P\propto t_{\rm M}^{3}$ in the shorttime regime and as $P\propto t_{\rm M}^{1}$ in the longtime regime. Additionally, considering the energy cost for erasing the MD's memory required by Landauer's principle, there exists a threshold time that guarantees QSE to output positive work.
 Publication:

arXiv eprints
 Pub Date:
 March 2023
 DOI:
 10.48550/arXiv.2303.14619
 arXiv:
 arXiv:2303.14619
 Bibcode:
 2023arXiv230314619Z
 Keywords:

 Quantum Physics;
 Condensed Matter  Statistical Mechanics
 EPrint:
 6+10 pages, 3+4 figures, Comments are welcome