学科分类
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1 个结果
  • 简介:BasedontheHolsteinmodelHamiltonianofone-dimensionalmolecularcrystals,bymakinguseoftheexpansionapproachofthecorrelatedsqueezed-coherentstatesofphononinsteadofthetwo-phononcoherentstateexpansionscheme,thepropertiesofthegroundstateandtheanomalousquantumfluctuationsareinvestigatedinastronglycoupledelectron-phononsystemwithspecialconsiderationoftheelectron-two-phononinteraction.Theeffectiverenormalization(αi)ofthedisplacementofthesqueezedphononswiththeeffectofthesqueezed-coherentstatesofphononandboththeelectron-displacedphononandthepolaron-squeezedphononcorrelationshavebeencombinedtoobtaintheanomalousquantumfluctuationsforthecorrectionsofthecoherentstate.Duetothesenon-adiabaticcorrelations,theeffectivedisplacementparameterαiislargerthantheordinaryparameterα(0)i.Incomparisonwiththeelectron-one-phononinteraction(g)correctedasαig,wehavefoundtheelectron-two-phononinteraction(g1)correctedasαi2g1isenhancedsignificantly.Forthisreason,thegroundstateenergy(E(2)0)contributedbytheelectron-two-phononinteractionismorenegativethanthesingle-phononcase(E(1)0)andthesolitonsolutionismorestable.Atthesametime,theeffectsoftheelectron-two-phononinteractiongreatlyincreasethepolaronenergyandthequantumfluctuations.Furthermore,inadeeperlevel,wehaveconsideredtheeffectofthepolaron-squeezedphononcorrelation(f-correlation).Sincethiscorrelationparameterf>1,thiseffectwillstrengthentheelectron-oneandtwo-phononinteractionsbyfαigandf2αi2g1,respectively.Thefinalresultsshowthatthegroundstateenergyandthepolaronenergywillappearmorenegativefurtherandthequantumfluctuationswillgainfurtherimprovement.

  • 标签: 一维分子晶体 极化声子 相互作用 量子波动 电子流 非绝热