D-Dimensional Dirac Fermions BEC-BCS Crossover Thermodynamics

(整期优先)网络出版时间:2007-07-17
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<正>AneffectiverelativisticcontinuummassiveProcaLagrangianactionisusedtoaccountfortheLorentzvectorcondensationeffectsontheequationofstateofthestronglyinteractingfermionssystem.TheinteriorquantumfluctuationeffectsareincorporatedasanexternalfieldapproximationindirectlythroughafictivegeneralizedThomsonProblemcountertermbackground.Thegeneralanalyticalformulasforthed-dimensionalthermodynamicsaregivenneartheunitarylimitregion,Inthenon-relativisticlimitford=3,theuniversaldimensionlesscoefficientε=4/9andenergygap△/ε_f=5/18arereasonablyconsistentwiththeexistingtheoreticalandexperimentalresults.Intheunitarylimitford=2andT=0,theuniversalcoefficientcanevenapproachtheextremeoccasionξ=0correspondingtotheinfiniteeffectivefermionmassm~*=∞,whichcanbemappedtothestronglycoupledtwo-dimensionalelectronsandisquitesimilartothethree-dimensionalBose-Einsteincondensationofidealbosongas.Instead,ford=1,theuniversalcoefficientξisnegative,implyingthenon-existenceofphasetransitionfromsuperfluiditytonormalstate.ThesolutionsmanifestthequantumIsinguniversalclasscharacteristicofthestronglycoupledunitaryfermionsgas.