简介:Basedonthesecond-ordermoments,thispaperderivesananalyticalexpressionoftheM2factoroffour-petalGaussianbeam.TheresultsshowthattheM2factorisonlydeterminedbythebeamordern.Thecorrespondingnumericalcalculationsarealsogiven.Asthebeamorderincreases,theaugmentofM2factorisdisciplinary.AstheexpressionofM2factorisexpressedinseriesformandbecomesmorecomplicated,anewconciseformulaofM2factorisalsopresentedbyusingcurvefittingofnumericalcalculations.When3≤n≤200,themaximumerrorrateoffittingformulawillnotexceed2.6%andtheaverageerrorrateis0.28%.Thisresearchishelpfultotheapplicationsoffour-petalGaussianbeam.
简介:Atheoreticalresearchonthevariationoftheabsorptionanddispersionprofilesandpopulationdistributionofeachlevelinaladder-four-levelsystemdrivenbytwocoherentfieldshasbeenmade.Whetherthevariationoccursornotdependsontheeffectofquantuminterference,thedetuningoftheuppercoherentfieldandtheseparationofthetwointermediatelevels.Adressed-stateanalysisisintroducedtoexplainthenumericalresults.
简介:Weproposeaschemeforteleportationoffour-levelatomicstatesinthermalcavities.TheschemedoesnotinvolvethegeneralizedBell-stateorgeneralizedGHZ-statemeasurement,whichisdifficultinpractice.Anotherfeatureoftheschemeisthatitdoesnotrequireindividualaddressingofatomsincavityandisinsensitivetobothcavitydecayandthermalfield,whichisofimportanceinpointofexperiment.
简介:Thefour-particleEPRentangledstate|p,x2,x3,x4〉isconstructed.Thecorrespondingquantummechanicaloperatorwithrespecttotheclassicaltransformationp→eλ1p,x2→eλ2x2,xs→eλ3x3,andx4→eλ4x4inthestate|p,x2,x3,x4〉isinvestigated,andthefour-moderealizationoftheSU(1,1)Liealgebraaswellasthecorrespondingsqueezingoperatorsarepresented.
简介:Weinvestigatetheentanglementtransferinafour-qubitsystemandcalculatetheconcurrencebetweenanytwoqubitsindifferentinitialstates.Weshowthatboththepureentangledstateandmixedentangledstatecanbetransferred.Forsomespecialcouplingconstantsandsomeevolutiontime,entanglementcanbecompletelytransferredfromonepairparticlestoanother.
简介:Agraphene-coatedmicrofiber(GCM)-basedhybridwaveguidestructureformedbywrappingmonolayergraphenearoundamicrofiberwithlengthofseveralmillimetersispumpedbyananosecondlaserat~1550nm,andmultiordercascadedfour-wave-mixing(FWM)iseffectivelygenerated.Byoptimizingboththedetuningandthepumppower,suchaGCMdevicewithhighnonlinearityandcompactsizewouldhavepotentialforawiderangeofFWMapplications,suchasphase-sensitiveamplification,multi-wavelengthfilter,all-opticalregenerationandfrequencyconversion,andsoon.
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简介:High-dimensionalentanglementisavaluableresourceforsecureandefficientquantuminformationprocessing.Amajorchallengeforpracticaluseofmultidimensionalquantumsystemsistheestablishmentofcontrolsoverarbitrarysuperpositionstatesinrealisticconditions.Thisworkdemonstratesspatiallyentangledphotonpairspropagatingthroughtwoseparatefour-coreopticalfiberswiththeamplitudesandphasesofthesuperpositionbeingindependentlycontrollable.Usingquantumstateanalyzersthatcandetectarbitrarymulticoresuperpositionstates,Bell-typeCGLMPinequalitiesintwo,three,andfourdimensionsaredirectlytested.Enhancedviolationoftheinequalitybyslightnonmaximalityofentanglementisalsodemonstrated.