三角光晶格上超冷玻色气体的量子相变PPT课件

1、三角光晶格上超冷玻色气体的量子相变姜 颖上海大学第六届全国冷原子物理和量子信息青年学者学术讨论会 浙江 金华 20122021-12-132 浙江师范大学Greiner et. al. Nature 415, 39 (2002)Stoof. Nature 415, 25 (2002)2021-12-13 浙江师范大学3Becker et. al. NJP12, 065025 (2010)2021-12-13 浙江师范大学4Quantum phase diagramsTime-of-flight picture and visibility2021-12-13 浙江师范大学5The modelJ

2、aksch et. al. PRL81, 3108 (1998)Many-body HamiltonianField operator expansionBose-Hubbard Hamiltonian2021-12-13 浙江师范大学6Quantum phase diagrams2021-12-13 浙江师范大学7The methodsOosten et. al. PRA63, 053601 (2001)Bogoliubov limitMean-field calculation Strong coupling expansionField theoretical methoddos San

3、tos et al. PRA (2009)cannot reveal the SF-MI phase transitionFisher et. al. PRB (1989)Freericks et. al. PRB (1996)2021-12-13 浙江师范大学8Effective potentialSuperfluid order parameterFree energy2021-12-13 浙江师范大学9Effective potentialEffective potentialThe phases of the original physical system correspond to

4、 the saddle points of the effective potential. Phase boundary determined by2021-12-13 浙江师范大学10Perturbation expansion2021-12-13 浙江师范大学11Perturbation expansionDiagrammatic expressions of for triangular lattice, hexagonal lattice and Kagome lattice2021-12-13 浙江师范大学12Quantum phase diagramsTriangular lat

5、ticeHexagonal latticeKagome latticeComparisonthe tip of the first lopeOur result: 0.03406Strong coupling expansion result: 0.037785Process chain approach numerical result: 0.03759Less than 10% deviationElstner et. al. PRB (1999)Teichmann et. al. EPL (2010)Lin, Zhang, YJ. PRA 85, 023619 (2012)2021-12

6、-13 浙江师范大学13Time-of-flight picture and visibility2021-12-13 浙江师范大学14Momentum distribution functionMomentum distribution function2021-12-13 浙江师范大学15Greens functions and linked cluster expansionOne-particle Greens functionn-particle Greens function associated with H0m-th cumulant2021-12-13 浙江师范大学16Gre

7、ens functions and linked cluster expansionDiagrammatic representation2021-12-13 浙江师范大学17Re-summed Greens functions2021-12-13 浙江师范大学18Momentum distribution functionFact of experiment3-dimensional systemLayered structureBecker et. al. NJP12, 065025 (2010)2021-12-13 浙江师范大学19Time-of-flight absorption picturesLin, Zhang, YJ arXiv: 1205.6949 (2012)2021-12-13 浙江师范大学20VisibilityLin, Zhang, YJ a