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dc.contributor.authorWiseman, Howarden_US
dc.contributor.authorVaccaro, J.en_US
dc.date.accessioned2017-05-03T11:50:57Z
dc.date.available2017-05-03T11:50:57Z
dc.date.issued2002en_US
dc.date.modified2009-09-03T07:13:28Z
dc.identifier.issn10502947en_US
dc.identifier.doi10.1103/PhysRevA.65.043606en_AU
dc.identifier.urihttp://hdl.handle.net/10072/6958
dc.description.abstracts discussed in the preceding paper [Wiseman and Vaccaro, preceding paper, Phys. Rev. A 65, 043605 (2002)], the stationary state of an optical or atom laser far above threshold is a mixture of coherent field states with random phase, or, equivalently, a Poissonian mixture of number states. We are interested in which, if either, of these descriptions of ?ss as a stationary ensemble of pure states, is more natural. In the preceding paper we concentrated upon the question of whether descriptions such as these are physically realizable (PR). In this paper we investigate another relevant aspect of these ensembles, their robustness. A robust ensemble is one for which the pure states that comprise it survive relatively unchanged for a long time under the system evolution. We determine numerically the most robust ensembles as a function of the parameters in the laser model: the self-energy ? of the bosons in the laser mode, and the excess phase noise ?. We find that these most robust ensembles are PR ensembles, or similar to PR ensembles, for all values of these parameters. In the ideal laser limit (?=?=0), the most robust states are coherent states. As the phase noise or phase dispersion is increased through ? or the self-interaction of the bosons ?, respectively, the most robust states become more and more amplitude squeezed. We find scaling laws for these states, and give analytical derivations for them. As the phase diffusion or dispersion becomes so large that the laser output is no longer quantum coherent, the most robust states become so squeezed that they cease to have a well-defined coherent amplitude. That is, the quantum coherence of the laser output is manifest in the most robust PR ensemble being an ensemble of states with a well-defined coherent amplitude. This lends support to our approach of regarding robust PR ensembles as the most natural description of the state of the laser mode. It also has interesting implications for atom lasers in particular, for which phase dispersion due to self-interactions is expected to be large.en_US
dc.description.peerreviewedYesen_US
dc.description.publicationstatusYesen_AU
dc.format.extent897974 bytes
dc.format.mimetypeapplication/pdf
dc.languageEnglishen_US
dc.language.isoen_AU
dc.publisherAmerican Physical Societyen_US
dc.publisher.placeUSAen_US
dc.publisher.urihttp://pra.aps.org/en_AU
dc.relation.ispartofpagefrom043606.1en_US
dc.relation.ispartofpageto043606.15en_US
dc.relation.ispartofjournalPhysical Review A: Atomic, Molecular and Optical Physicsen_US
dc.relation.ispartofvolume65en_US
dc.subject.fieldofresearchcode240201en_US
dc.titleAtom lasers, coherent states, and coherence: II. Maximally robust ensembles of pure states.en_US
dc.typeJournal articleen_US
dc.type.descriptionC1 - Peer Reviewed (HERDC)en_US
dc.type.codeC - Journal Articlesen_US
gro.rights.copyrightCopyright 2002 American Physical Society. This is the author-manuscript version of this paper. Reproduced in accordance with the copyright policy of the publisher. Please refer to the journal link for access to the definitive, published version.en_AU
gro.date.issued2002
gro.hasfulltextFull Text


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