Coherence-enhanced efficiency of feedback-driven quantum engines

dc.contributor.authorBrandner, Kay
dc.contributor.authorBauer, Michael
dc.contributor.authorSchmid, Michael T.
dc.contributor.authorSeifert, Udo
dc.date.accessioned2024-12-20T15:02:49Z
dc.date.available2024-12-20T15:02:49Z
dc.date.issued2015de
dc.date.updated2023-11-14T03:00:29Z
dc.description.abstractA genuine feature of projective quantum measurements is that they inevitably alter the mean energy of the observed system if the measured quantity does not commute with the Hamiltonian. Compared to the classical case, Jacobs proved that this additional energetic cost leads to a stronger bound on the work extractable after a single measurement from a system initially in thermal equilibrium (2009 Phys. Rev. A 80 012322). Here, we extend this bound to a large class of feedback-driven quantum engines operating periodically and in finite time. The bound thus implies a natural definition for the efficiency of information to work conversion in such devices. For a simple model consisting of a laser-driven two-level system, we maximize the efficiency with respect to the observable whose measurement is used to control the feedback operations. We find that the optimal observable typically does not commute with the Hamiltonian and hence would not be available in a classical two level system. This result reveals that periodic feedback engines operating in the quantum realm can exploit quantum coherences to enhance efficiency.en
dc.identifier.issn1367-2630
dc.identifier.other1915213932
dc.identifier.urihttp://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-154856de
dc.identifier.urihttp://elib.uni-stuttgart.de/handle/11682/15485
dc.identifier.urihttp://dx.doi.org/10.18419/opus-15466
dc.language.isoende
dc.relation.uridoi:10.1088/1367-2630/17/6/065006de
dc.rightsinfo:eu-repo/semantics/openAccessde
dc.rights.urihttps://creativecommons.org/licenses/by/3.0/de
dc.subject.ddc530de
dc.titleCoherence-enhanced efficiency of feedback-driven quantum enginesen
dc.typearticlede
ubs.fakultaetMathematik und Physikde
ubs.institutInstitut für Theoretische Physik IIde
ubs.publikation.seiten10de
ubs.publikation.sourceNew journal of physics 17 (2015), No. 065006de
ubs.publikation.typZeitschriftenartikelde

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