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dc.contributor.authorWiseman, Howarden_US
dc.contributor.authorC. Doherty, Andrewen_US
dc.contributor.editorHeszler, P.en_US
dc.date.accessioned2017-05-03T16:57:54Z
dc.date.available2017-05-03T16:57:54Z
dc.date.issued2004en_US
dc.date.modified2009-10-13T21:52:22Z
dc.identifier.doi10.1117/12.547492en_AU
dc.identifier.urihttp://hdl.handle.net/10072/26025
dc.description.abstractQuantum feedback control is the control of the dynamics of a quantum system by feeding back (in real time) the results of monitoring that system. For systems with linear dynamics, the control problem is amenable to exact analysis. In these cases, the quantum system is equivalent to a stochastic system of classical phase-space variables with linear drift and constant diffusion, and with a measured current (e.g. a homodyne photocurrent) linear in the system variables. However, the classical evolution is constrained in order to represent valid quantum evolution. We quantify this in terms of a linear matrix inequality (LMI) relating the drift and diffusion (a sort of zero temperature fluctuation-dissipation theorem), and another LMI for the covariance matrix of the possible conditioned states (i.e. under all possible monitoring schemes consistent with the master equation). For manipulable systems (i.e. where the experimenter has arbitrary control over the parameters in a Hamiltonian linear in the system variables) the covariance of the conditioned state is all that is needed to calculate the effectiveness of the feedback. In this case the double optimization problem reduces to a semidefinite program, which can be solved efficiently in general. We illustrate this with an example drawn from quantum optics.en_US
dc.description.peerreviewedYesen_US
dc.description.publicationstatusYesen_AU
dc.format.extent6644662 bytes
dc.format.mimetypeapplication/pdf
dc.languageEnglishen_US
dc.language.isoen_AU
dc.publisherSPIEen_US
dc.publisher.placeBellingham, WA, USAen_US
dc.publisher.urihttp://spiedl.org/dbt/dbt.jsp?KEY=PSISDG&Volume=5468&Issue=1&bproc=symp&scode=FN04en_AU
dc.relation.ispartofconferencenameFluctuations and noise in photonics and quantum optics II.en_US
dc.relation.ispartofconferencetitleFluctuations and noise in photonics and quantum optics II. SPIE proceedings 5468en_US
dc.relation.ispartofdatefrom2004-05-26en_US
dc.relation.ispartofdateto2004-05-28en_US
dc.relation.ispartoflocationMaspalomas, Spainen_US
dc.subject.fieldofresearchQuantum Physics not elsewhere classifieden_US
dc.subject.fieldofresearchcode020699en_US
dc.titleOpen quantum systems with linear dynamics: optimal unravellings for optimal feedback controlen_US
dc.typeConference outputen_US
dc.type.descriptionE1 - Conference Publications (HERDC)en_US
dc.type.codeE - Conference Publicationsen_US
gro.rights.copyrightCopyright 2004 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.en_AU
gro.date.issued2004
gro.hasfulltextFull Text


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