超流費米原子氣體的自旋響應.pdf

1、大連理工大學碩士學位論文超流費米原子氣體的自旋響應姓名：李海玲申請學位級別：碩士專業(yè)：凝聚態(tài)物理指導教師：韓福祥20060601塑墮塑鲞堅蘭笪塑!墼墮壁SpinresponsesofasuperfluidFermigasofatomsAbstract曩le豫alizifionofultraeoldFermigasesof韙tomsbringsaneweratothe也eoreticalandexperimentalresearchond

2、egeneratequantmnFeimigasesSincethen，BardeenCooperSchrieffer(BCS)condensationoffeimionicatomsandBoseEinsteincondensation(BEC)ofdiat∞icmoleculesofthese3鏹msasweljastheBCSBECcrossoverregimeshavestimulatedagreatinterestInthis

3、paperwestudythedynamicspinresponsesatfinitetemperatures誼thesuperfluidstateontheBCSsideoftheBCSBECcrossoverregimeThisdissertationisorganizedasfollowsInChaper。thepreparationof矗nultraco艇Fermigasofatomsisdescdbed1nChaperII。F

4、eshbaehresonanceisinlroducedThesignofthetwobodyinteraefionbetweenatomscartbetunedwiththemagneticfieldFeshbachresononceInChapor疆byusingthepathintegrarepresentationofthegrandpartitionfunctioninvestigatethenatureofcondensat

5、ionontheBECsideoftheBCS—BECcrossoverregimeFromtheselfconsistentequations，wehavefoundthatBCScondensationofatomscan’toccnPinsucharepulsivetWObe母interactlonFermigasofatoms。Tosubstantiateonrconclusionsfromtheselfconsistenteq

6、uationsfortheorderparameters，theeffectiveatom—atominteraetionmediatedthroughmoleculeshasalsobeencomputedwi也theFoldyWouthuysantransformationandhasbeenfoundtoberepulsivewhichimpliesthe曲senceofBCScondensationofatomsontheBEC

7、sideoftheBCSBECcrossoverregime1nChaperlvthedynamicspinstructurefactoratfinitetemparaturesiuasuperfluidFermigasofatomsontheBCSsideoftheBCS—BECcrossoverregimehasbeenstudled，ithasbeenfoundthatthedynamicspinstructurefactorpo

8、ssessesasmalIpeakforfrequenciestessthantwicetheenergygapandthepeakpositiondependendsonwaveveator；thedynamiaspinslructtlrefactofstartstoincreasemonotomicallywithfrequencies砒twicetheenergygapThepeakinthedynamicspinstructur

9、efactoratthefinitewaveveetorimpliesthepossiblecoexistenceoftheantiferromagnericphasewiththesuperfluid埔aseinultracoldFermigasesofatoms圈1isphenomenonhassignigicentimplicationsonhightemperaturesuperconductivity，sinceantifer