Stabilizing open quantum batteries by sequential measurements

Year: 2020

Authors: Gherardini S.; Campaioli F.; Caruso F.; Binder F.C.

Autors Affiliation: Department of Physics and Astronomy & LENS, University of Florence, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy. School of Physics and Astronomy, Monash University, Victoria 3800, Australia. Department of Physics and Astronomy & LENS, University of Florence, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy. Institute for Quantum Optics and Quantum Information – IQOQI Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria.

Abstract: A quantum battery is a work reservoir that stores energy in quantum degrees of freedom. When immersed in an environment, an open quantum battery needs to be stabilized against free-energy leakage due to decoherence, unavoidably entailing entropy production. For this purpose we here propose a stabilization protocol given by a nonunitary open-loop control action able to compensate for the entropy increase and to maintain the open quantum battery in its highest ergotropy state. The protocol relies on nonselective, frequent, projective measurements that are interspersed by optimized time intervals. In accordance with a second-law-like inequality derived for the entropy production rate of the controlled battery, the proposed procedure results in minimized control power. The effectiveness of the method is finally tested on a qubit subject to decoherence, achieving an average fidelity value around 95%.

Journal/Review: PHYSICAL REVIEW RESEARCH

Volume: 2      Pages from:   to:

More Information: This work was financially supported by the Fondazione CR Firenze through the project Q-BIOSCAN and QUANTUMAI, PATHOS EU H2020 FET-OPEN Grant No. 828946, and UNIFI Grant Q-CODYCES. F.C.B. acknowledges funding from the European Union´s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 801110 and the Austrian Federal Ministry of Education, Science and Research (BMBWF).
KeyWords: Quantum batteries, nonunitary open-loop control, sequential quantum measurements, Quantum system stabilisation
DOI: 10.1103/PhysRevResearch.2.013095