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arXiv · 1905.10262

Maximal energy extraction via quantum measurement

Andrea Solfanelli·Lorenzo Buffoni·Alessandro Cuccoli·Michele Campisi
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Abstract

We study the maximal amount of energy that can be extracted from a finite quantum system by means of projective measurements. For this quantity we coin the expression "metrotropy" $\mathcal{M}$, in analogy with "ergotropy" $\mathcal{W}$, which is the maximal amount of energy that can be extracted by means of unitary operations. The study is restricted to the case when the system is initially in a stationary state, and therefore the ergotropy is achieved by means of a permutation of the energy eigenstates. We show that i) the metrotropy is achieved by means of an even combination of the identity and an involution permutation; ii) it is $\mathcal{M}\leq\mathcal{W}/2$, with the bound being saturated when the permutation that achieves the ergotropy is an involution.

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Andrea Solfanelli, Lorenzo Buffoni, Alessandro Cuccoli, Michele Campisi. 2019-09-08. Maximal energy extraction via quantum measurement. https://doi.org/10.1088/1742-5468%2Fab3721

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