简介:在前後一致的Hartree-Fock近似以内,一在为不同类的Bose气体的扎根的州的精力的这近似表情明确是被导出一Bose爱因斯坦冷凝物的不同类的密度功能。获得的结果与Bose爱因斯坦冷凝物为系统在单个粒子的密度矩阵基于离开斜的远程的顺序的存在。这使避免异常一般水准的使用可能。动能的明确的形式,在Gross-Pitaevski途径不同于一个,被发现。动能的获得的形式在Hartree-Fock近似以外是有效的并且能被申请任意的强壮的interparticle相互作用。
简介:ThecomparativenumericalandanalyticalanalysisofscintillationindicesofthevortexLaguerre–GaussianbeamandthenonvortexdoughnutholeandGaussianbeamspropagatingintherandomlyinhomogeneousatmospherehasbeenperformed.Ithasbeenfoundthatthedependenceofthescintillationindexattheaxisoftheopticalvortexontheturbulenceintensityatthepathhastheformofaunitstep.Ithasbeenshownthatthebehaviorofscintillationsinthecrosssectionsofvortexandnonvortexbeamsdifferswidely.DespitethescintillationindexofvortexbeamshasbeencalculatedonlyforthesimplestLG10mode,theobtainedresultsarequitegeneral,becausetheydemonstratethemainpropertiesinherentinscintillationsofvortexbeamsofanytype.
简介:WestudythermodynamicsoftheparabolicLemaitre-Tolman-Bondi(LTB)cosmologysupportedbyaperfectSuidsource.ThismodelisthenaturalgeneralizationoftheSatFriedmann-Robertson-Walker(FRW)universe,anddescribesaninhomogeneousuniversewithsphericalsymmetry.AfterreviewingsomebasicequationsintheparabolicLTBcosmology,weobtainarelationforthedecelerationparameterinthismodel.Wealsoobtainaconditionforwhichtheuniverseundergoesanacceleratingphaseatthepresenttime.WeusethefirstlawofthermodynamicsontheapparenthorizontogetherwiththeEinsteinfieldequationstogetarelationfortheapparenthorizonentropyinLTBcosmology.WefindoutthatinLTBmodelofcosmology,theapparenthorizon’sentropycouldbefeededbyaterm,whichincorporatestheeffectsoftheinhomogeneity.Weconsiderthisresultandgetarelationforthetotalentropyevolution,whichisusedtoexaminethegeneralizedsecondlawofthermodynamicsforanacceleratinguniverse.WealsoverifythevalidityofthesecondlawandthegeneralizedsecondlawofthermodynamicsforauniversefilledwithsomekindsofmattersboundedbytheeventhorizonintheframeworkoftheparabolicLTBmodel.
简介:Thethermalentanglementofatwo-qubitanisotropicHeisenbergXYZchainunderaninhomogeneousmagneticfieldbisstudied.Itisshownthatwheninhomogeneityisincreasedtoacertainvalue,theentanglementcanexhibitalargerrevivalthanthatoflessvaluesofb.Thepropertyisbothtrueforzerotemperatureandafinitetemperature.Theresultsalsoshowthattheentanglementandthresholdtemperaturecanbeincreasedbyincreasinginhomogeneousexternalmagneticfield.
简介:Basedonthetheoryofcomplexfunctionandtheprincipleofhomogenization,harmonicdynamicsstressofaradiallyinfiniteinhomogeneousmediumwithacircularcavityisinvestigated.Duetothesymmetry,wavevelocityisassumedtohavepower-lawvariationintheradialdirectiononly,andtheshearmodulusisconstant.TheHelmholtzequationwithavariablecoefficientisequivalentlytransformedintoastandardHelmholtzequationwithageneralconformaltransformationmethod(GCTM).Thedisplacementsandstressfieldsareproposed.Numericalresultsshowthatthewavenumberandtheinhomogeneityparameterofthemediumhavesignificanteffectsonthedynamicstressconcentrationaroundthecircularcavity.Thedynamicstressconcentrationfactor(DSCF)becomessingularwhentheinhomogeneityparameterofmediumisclosetozero.
简介:Wetheoreticallyinvestigatehigh-orderharmonicgenerationinatwo-colormulti-cycleinhomogeneousfieldcombinedwitha27thharmonicpulse.Byconsideringabowtie-shapedgoldnanostructure,thespatiotemporalprofilesofenhancedplasmonicfieldsareobtainedbysolvingtheMaxwellequationusingfinite-domaintime-differencemethod.Basedonquantum-mechanicalandclassicalmodels,theeffectof27thharmonicpulse,temporalprofileofenhancedplasmonicfieldandinhomogeneityonsupercontinuumgenerationareanalyzedanddiscussed.Asaresult,broadbandsupercontinuumcanbegeneratedfromourapproachwithoptimizedgapsizeofnanostructure.Moreover,theseresultsarenotsensitivelydependentontherelativephaseinthetwo-colorfield.
简介:Wereporttheobservationofelectricfieldinducedrandomlasinginadyedopedliquidcrystalsystem.ThiswasachievedbyusingaliquidcrystalhostwithnegativedielectricanisotropydopedwithlaserdyePM597ina75μmcellwithahomeotropicalignmentlayer.Intheabsenceofanappliedfield,onlyamplifiedspontaneousemissionwasobservedsincetheliquidcrystalorientationwasuniform.However,applicationofafieldresultedinafieldinducedplanar-likeconfigurationwithlocalnonuniformityinliquidcrystalorientation.Thisledtorandomlasingintheenergizedstate(voltagegreaterthanatransitionthreshold).Theonsetoflasingoccursbyapplicationofeitheraspatiallyhomogenousoraspatiallyinhomogeneouselectricfieldacrosstheliquidcrystal.Thecharacteristicsoftheemissionspectraasafunctionofdifferent(i)dyeconcentrationand(ii)appliedvoltagewereinvestigatedusingnanosecondpulsedlaserexcitationat532nm.Theeffectsofusinganinhomogeneousfieldwerecomparedtotheuseofahomogenousfieldandreported.Itisshownthatthespatialconfigurationcanbeusedtoaltertheemissionspectraofthesystem.Theworkisusedtosuggestanewconfiguration,referredtohereas'reversemode,'forliquidcrystal-basedrandomlasers.Thisnewconfigurationmayprovideadditionalavenuesfortheiruseincommercialdevices.