光格子中玻色-愛因斯坦凝聚體的超流-絕緣相變.pdf

1、噫796幺78分類號密級單位代碼!!!!!學(xué)號西北大學(xué)碩士學(xué)位論文題目當(dāng)揸王生遮魚=愛固塹塑遂鐾住數(shù)趨速：絲緣擔(dān)壅S叢衛(wèi)星r旦叢i亟：叢Q!!!n墨叢!叢Qr里h壘s璺丑i趣si!iQ照Q!旦Q墨曼二曼in!塑i旦￡Q塾魚星旦墨叢星墨i墜Q衛(wèi)!i曼魚!L墾煎i￡星作者瑟透指導(dǎo)教師量盟塞：割魚嚙專業(yè)技術(shù)職務(wù)麴援!班窒雖學(xué)科(專業(yè))趟聚查翅堡答辯日期—上0墮』——學(xué)位授予日期二00五年四月AbstractTherealizationofBo

2、se—Einsteincondensation(BEC)indiluteatomicgases，itnotonlyprovedEinstein’sprediction，butalsoprovidesanewwaytostudythedynamicsofatomandsomephysicalphenomenainlowtemperatureBecauseofatom’Squantumeffectinlowtemperature，theat

3、omofcondensatescantunnellinginopticallattice，thisisinsuperfluidphaseAsthepotentialdepthofthelatticeisincreased，theatomisconfined，atransitionisobservedfromasuperfluidtoaMottinsulatorphaseInthesuperfluidphase，eachatomisspr

4、eadoutovertheentirelattice，withlongrangephasecoherenceButintheinsulatingphase，exactnumbersofatomsarelocalizedatindividuallatticesites，withnophasecoherenceacrossthelatticeTheexcitationspectrumisgaplessinsuperfluidphasewhe

5、reasexhibitsagapintheMottinsulatorphaseWegettheEnergyspectrumoftwocomponentBECbyGreenfunctiontechniqueandanalyzesuperfluid—Mottinsulatorphasetransition，andphasediagrambymean—fieldapproachThispapercontainsfourchaptersChap

6、terlreviewsrecentinvestigationinBoseEinsteincondensation，andanalyzescriticalpointandconditionofphasetran—sitionChapter2introducestheexperimentofMottinsulatorandsuperfluidphasetransitionindiluteatomicgases，theoreticmodean

7、dsomestudyingInchapter3，westudytheinfluenceofdipoledipoleinteraction(itislongrange)oftwocompo—nentBECinopticallattice，byGreenfunctiontechniqueandmeanfieldapproachTheresultsshowthatlongrangeinteractionanddipoledipoleinter

8、actioncanbestronglyinfluencethephasetransitionoftwocomponentInchapter4，wesummarizethispaperKeywords：Bose—E：nsteinCondensation，PhaseTransition，BoseHubbardMode，Twocomponent，GreenFunction，Longrangeinteraction，Dipoleinteract