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dc.contributor.authorSokolovski, D.
dc.contributor.authorRusconi, S. 
dc.contributor.authorBrouard, S.
dc.contributor.authorAkhmatskaya, E. 
dc.date.accessioned2017-04-24T15:14:27Z
dc.date.available2017-04-24T15:14:27Z
dc.date.issued2017-04-10
dc.identifier.issn2469-9926
dc.identifier.urihttp://hdl.handle.net/20.500.11824/668
dc.description.abstractImposing restrictions on the Feynman paths of the monitored system has in the past been proposed as a universal model-free approach to continuous quantum measurements. Here we revisit this proposition and demonstrate that a Gaussian restriction, resulting in a sequence of many highly inaccurate (weak) von Neumann measurements, is not sufficiently strong to ensure proximity between a readout and the Feynman paths along which the monitored system evolves. Rather, in the continuous limit, the variations of a typical readout become much larger than the separation between the eigenvalues of the measured quantity. Thus, a typical readout is not represented by a nearly constant curve, correlating with one of the eigenvalues of the measured quantity $\hat{A}$, even when decoherence or Zeno effect is achieved for the observed two-level system, and does not point directly to the system's final state. We show that the decoherence in a ``free'' system can be seen as induced by a Gaussian random walk with a drift, eventually directing the system towards one of the eigenstates of $\hat{A}$. A similar mechanism appears to be responsible for the Zeno effect in a driven system, when its Rabi oscillations are quenched by monitoring. Alongside the Gaussian case, which can only be studied numerically, we also consider a fully tractable model with a ``hard wall'' restriction and show the results to be similar.en_US
dc.description.sponsorshipMINECO, Fondo Europeo de Desarrollo Regional FEDER, Grant No. FIS2015-67161-P (MINECO/FEDER) (D.S.), MINECO Grant No. SVP-2014-068451 (S.R.), MINECO Grant No. MTM2013-46553-C3-1-P (E.A.), SGI/IZOSGIker UPV/EHU, i2BASQUE academic network,en_US
dc.formatapplication/pdfen_US
dc.language.isoengen_US
dc.rightsReconocimiento-NoComercial-CompartirIgual 3.0 Españaen_US
dc.rights.urihttp://creativecommons.org/licenses/by-nc-sa/3.0/es/en_US
dc.subjectRestrictions on Feynman pathsen_US
dc.subjectweak von Neumann measurementsen_US
dc.subjectcontinuous limiten_US
dc.subjectZeno effecten_US
dc.subjectRabi oscillationsen_US
dc.titleReexamination of continuous fuzzy measurement on two-level systemsen_US
dc.typeinfo:eu-repo/semantics/articleen_US
dc.identifier.doi10.1103/PhysRevA.95.042111
dc.relation.publisherversionhttps://journals.aps.org/pra/abstract/10.1103/PhysRevA.95.042111en_US
dc.relation.projectIDES/1PE/SEV-2013-0323en_US
dc.relation.projectIDES/1PE/MTM2016-76329-Ren_US
dc.relation.projectIDEUS/BERC/BERC.2014-2017en_US
dc.rights.accessRightsinfo:eu-repo/semantics/openAccessen_US
dc.type.hasVersioninfo:eu-repo/semantics/publishedVersionen_US
dc.journal.titlePHYSICAL REVIEW Aen_US


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Reconocimiento-NoComercial-CompartirIgual 3.0 España
Except where otherwise noted, this item's license is described as Reconocimiento-NoComercial-CompartirIgual 3.0 España