Evolution of the vortex state in the BCS-BEC crossover of a quasi two-dimensional superfluid Fermi gas

doi:10.1088/1674-1056/25/11/110306

中国物理B ›› 2016, Vol. 25 ›› Issue (11): 110306-110306.doi: 10.1088/1674-1056/25/11/110306

Evolution of the vortex state in the BCS-BEC crossover of a quasi two-dimensional superfluid Fermi gas

Xuebing Luo(罗学兵), Kezhao Zhou(周可召), Zhidong Zhang(张志东)

Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China

收稿日期:2016-03-30 修回日期:2016-06-28 出版日期:2016-11-05 发布日期:2016-11-05
通讯作者: Kezhao Zhou E-mail:kezhaozhou@gmail.com
基金资助:
Project supported by the National Natural Science Foundation of China (Grant Nos. 51331006, 51590883, and 11204321) and the Project of Chinese Academy of Sciences (Grant No. KJZD-EW-M05-3).

Evolution of the vortex state in the BCS-BEC crossover of a quasi two-dimensional superfluid Fermi gas

Xuebing Luo(罗学兵), Kezhao Zhou(周可召), Zhidong Zhang(张志东)

Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China

Received:2016-03-30 Revised:2016-06-28 Online:2016-11-05 Published:2016-11-05
Contact: Kezhao Zhou E-mail:kezhaozhou@gmail.com
Supported by:
Project supported by the National Natural Science Foundation of China (Grant Nos. 51331006, 51590883, and 11204321) and the Project of Chinese Academy of Sciences (Grant No. KJZD-EW-M05-3).

摘要/Abstract

摘要： We use the path-integral formalism to investigate the vortex properties of a quasi-two dimensional (2D) Fermi superfluid system trapped in an optical lattice potential. Within the framework of mean-field theory, the cooper pair density, the atom number density, and the vortex core size are calculated from weakly interacting BCS regime to strongly coupled while weakly interacting BEC regime. Numerical results show that the atoms gradually penetrate into the vortex core as the system evolves from BEC to BCS regime. Meanwhile, the presence of the optical lattice allows us to analyze the vortex properties in the crossover from three-dimensional (3D) to 2D case. Furthermore, using a simple re-normalization procedure, we find that the two-body bound state exists only when the interaction is stronger than a critical one denoted by G_c which is obtained as a function of the lattice potential's parameter. Finally, we investigate the vortex core size and find that it grows with increasing interaction strength. In particular, by analyzing the behavior of the vortex core size in both BCS and BEC regimes, we find that the vortex core size behaves quite differently for positive and negative chemical potentials.

关键词: ultra-cold quantum gases, superconductivity/superfluidity, vortex, BCS-BEC crossover

Abstract: We use the path-integral formalism to investigate the vortex properties of a quasi-two dimensional (2D) Fermi superfluid system trapped in an optical lattice potential. Within the framework of mean-field theory, the cooper pair density, the atom number density, and the vortex core size are calculated from weakly interacting BCS regime to strongly coupled while weakly interacting BEC regime. Numerical results show that the atoms gradually penetrate into the vortex core as the system evolves from BEC to BCS regime. Meanwhile, the presence of the optical lattice allows us to analyze the vortex properties in the crossover from three-dimensional (3D) to 2D case. Furthermore, using a simple re-normalization procedure, we find that the two-body bound state exists only when the interaction is stronger than a critical one denoted by G_c which is obtained as a function of the lattice potential's parameter. Finally, we investigate the vortex core size and find that it grows with increasing interaction strength. In particular, by analyzing the behavior of the vortex core size in both BCS and BEC regimes, we find that the vortex core size behaves quite differently for positive and negative chemical potentials.

Key words: ultra-cold quantum gases, superconductivity/superfluidity, vortex, BCS-BEC crossover

中图分类号: (Degenerate Fermi gases)

03.75.Ss

03.75.Lm (Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations) 37.10.Jk (Atoms in optical lattices)

罗学兵, 周可召, 张志东. Evolution of the vortex state in the BCS-BEC crossover of a quasi two-dimensional superfluid Fermi gas[J]. 中国物理B, 2016, 25(11): 110306-110306.

Xuebing Luo(罗学兵), Kezhao Zhou(周可召), Zhidong Zhang(张志东). Evolution of the vortex state in the BCS-BEC crossover of a quasi two-dimensional superfluid Fermi gas[J]. Chin. Phys. B, 2016, 25(11): 110306-110306.

参考文献 48

[1]	Anderson M H, Ensher J R, Matthews M R, Wieman C E and Cornell E A 1995 Science 269 198
[2]	DeMarco B and Jin D S 1999 Science 285 1703
[3]	Truscott A, Strecker K, McAlexander W, Partridge G and Hulet R G 2001 Science 291 2570
[4]	O'Hara K M, Hemmer S L, Gehm M E, Granade S R and Thomas J E 2002 Science 298 2179
[5]	Bourdel T, Cubizolles J, Khaykovich L, Magalhaes K, Kokkelmans S, Shlyapnikov G and Salomon C 2003 Phys. Rev. Lett. 91 020402
[6]	Bartenstein M, Altmeyer A, Riedl S, Jochim S, Chin C, Hecker-Denschlag J and Grimm R 2004 Phys. Rev. Lett. 92 120401
[7]	Bourdel T, Khaykovich L, Cubizolles J, Zhang J, Chevy F, Teichmann M, Tarruell L, Kokkelmans S J J M F and Salomon C 2004 Phys. Rev. Lett. 93 050401
[8]	Regal C A, Greiner M and Jin D S 2004 Phys. Rev. Lett. 92 040403
[9]	Zwierlein M W, Stan C A, Schunck C H, Raupach S M F, Kerman A J and Ketterle W 2004 Phys. Rev. Lett. 92 120403
[10]	Giorgini S, Pitaevskii L P and Stringari S 2008 Rev. Mod. Phys. 80 1215
[11]	Bloch I, Dalibard J and Zwerger W 2008 Rev. Mod. Phys. 80 885
[12]	Deng J, Diao P P, Yu Q L and Wu H B 2015 Chin. Phys. Lett. 32 53401
[13]	Chen K J and Zhang W 2014 Chin. Phys. Lett. 31 110303
[14]	Luan T, Jia T, Chen X Z and Ma Z Y 2014 Chhin. Phys. Lett. 31 43401
[15]	Qi X Y, Zhang A X and Xue J K 2013 Chin. Phys. Lett. 30 110305
[16]	Ruan X X, Gong H, Du L, Jiang Y, Sun W M and Zong H S 2013 Chin. Phys. Lett. 30 110303
[17]	Liu Y X, Ye J, Li Y Y and Zhang Y B 2015 Chin. Phys. B 24 86701
[18]	Feshbach H 1958 Ann. Phys. 5 357
[19]	Stoof H T C, Houbiers M, Sackett C A and Hulet R G 1996 Phys. Rev. Lett. 76 10
[20]	Bardeen J, Cooper L N and Schrieffer J R 1957 Phys. Rev. 108 1175
[21]	Eagles B 1969 Phys. Rev. 186 456
[22]	Leggett A J 1980 J. Phys. Colloq. 41 7
[23]	Zwierlein M W, Abo-Shaeer J R, Schirotzek A, Schunck C H and Ketterle W 2005 Nature 435 1047
[24]	Li S Q, Hu H and Liu X J 2008 Physics 37 141
[25]	Zhang J and Zhai H 2006 Physics 35 553
[26]	Lai X J, Cai X O and Zhang J F 2015 Chin. Phys. B 24 70503
[27]	Wen H H 2006 Physics 35 16
[28]	Wen H H 2006 Physics 35 111
[29]	Lü G, Cao X C, Qin Y F, Wang L H, Li G H, Gao F, Sun F W and Zhang H 2015 Acta Phys. Sin. 64 217501(in Chinese)
[30]	Sun L, Huo Y, Zhou C, Liang J H, Zhang X Z, Xu Z J, Wang Y and Wu Y Z 2015 Acta Phys. Sin. 64 197502(in Chinese)
[31]	Liu X L, Yang Y, Wu J P, Zhang Y F, Fan H M and Ding J 2015 Chin. Phys. B 24 127505
[32]	Sun M J and Liu Y W 2015 Acta Phys. Sin. 64 247505(in Chinese)
[33]	Bulgac A and Yu Y 2003 Phys. Rev. Lett. 91 190404
[34]	Hu H, Liu X J and Drummond P 2007 Phys. Rev. Lett 98 060406
[35]	Sensarma R, Randeria M and Ho T L 2006 Phys. Rev. Lett. 96 090403
[36]	Machida M and Koyama T 2005 Phys. Rev. Lett. 94 140401
[37]	de Gennes P G 1966 Superconductivity of Metals and Alloys (New York:Benjamin)
[38]	Tempere J, Wouters M and Devreese J T 2005 Phys. Rev. A 71 033631
[39]	Tempere J and Devreese J T 2006 Physica C 437-438 323
[40]	Tempere J and Devreese J T 2005 Path-integrals and the BEC/BCS Crossover in Dilute Atomic Gases. The 8-th International Conference "Path Integrals. From Quantum Information to Cosmology", Prague, Czech Republic
[41]	Altland A and Simons B D 2010 Condensed Matter Field Theory (Cambridge:Cambridge University Press)
[42]	Bhattacherjee A B 2007 J. Phys. B:At. Mol. Opt. Phys. 40 4453
[43]	De Palo S, Castellani C, Di Castro C and Chakraverty B K 1999 Phys. Rev. B 60 564
[44]	Orso G, Menotti C and Stringari S 2006 Phys. Rev. Lett. 97 190408
[45]	Wouters M and Orso G 2006 Phys. Rev. A 73 012707
[46]	Iskin M and Sá de Melo C A R 2009 Phys. Rev. Lett. 103 165301
[47]	Adhikari S K andSalasnich L 2008 Phys. Rev. A 78 043616
[48]	Adhikari S K 2010 J. Phys. B 43 085304

Evolution of the vortex state in the BCS-BEC crossover of a quasi two-dimensional superfluid Fermi gas

Evolution of the vortex state in the BCS-BEC crossover of a quasi two-dimensional superfluid Fermi gas

RichHTML

PDF (PC)

赞

可视化

摘要/Abstract

引用本文

使用本文

参考文献 48

相关文章 15

Metrics

本文评价

推荐阅读 0

[1]	Liping Zhang(张丽萍), Zuyu Xu(徐祖雨), Xiaojie Li(黎晓杰), Xu Zhang(张旭), Mingyang Qin(秦明阳), Ruozhou Zhang(张若舟), Juan Xu(徐娟), Wenxin Cheng(程文欣), Jie Yuan(袁洁), Huabing Wang(王华兵), Alejandro V. Silhanek, Beiyi Zhu(朱北沂), Jun Miao(苗君), and Kui Jin(金魁). Cascade excitation of vortex motion and reentrant superconductivity in flexible Nb thin films[J]. 中国物理B, 2023, 32(4): 47302-047302.
[2]	Delong Fang(方德龙). Vortex bound states influenced by the Fermi surface anisotropy[J]. 中国物理B, 2023, 32(3): 37403-037403.
[3]	Kang Chen(陈康), Zhi-Yuan Ma(马志远), and You-You Hu(胡友友). Tightly focused properties of a partially coherent radially polarized power-exponent-phase vortex beam[J]. 中国物理B, 2023, 32(2): 24208-024208.
[4]	Ling-Yun Shu(舒凌云), Ke Cheng(程科), Sai Liao(廖赛), Meng-Ting Liang(梁梦婷), and Ceng-Hao Yang(杨嶒浩). Asymmetrical spiral spectra and orbital angular momentum density of non-uniformly polarized vortex beams in uniaxial crystals[J]. 中国物理B, 2023, 32(2): 24211-024211.
[5]	Xiao-Ju Xue(薛晓菊), Bi-Jun Xu(徐弼军), Bai-Rui Wu(吴白瑞), Xiao-Gang Wang(汪小刚), Xin-Ning Yu(俞昕宁), Lu Lin(林露), and Hong-Qiang Li(李宏强). Generation of elliptical airy vortex beams based on all-dielectric metasurface[J]. 中国物理B, 2023, 32(2): 24215-024215.
[6]	Hua-Nan Li(李化南), Tong-Xin Xue(薛彤鑫), Lei Chen(陈磊), Ying-Rui Sui(隋瑛瑞), and Mao-Bin Wei(魏茂彬)^†. Influence of Dzyaloshinskii-Moriya interaction on the magnetic vortex reversal in an off-centered nanocontact geometry[J]. 中国物理B, 2022, 31(9): 97501-097501.
[7]	Zhen Liu(刘震), Zi-Xuan Yang(杨子萱), Chuan Xu(徐川), Jia-Ji Zhao(赵嘉佶), Lu-Junyu Wang(王陆君瑜), Yun-Qi Fu(富云齐), Xue-Lei Liang(梁学磊), Hui-Ming Cheng(成会明), Wen-Cai Ren(任文才), Xiao-Song Wu(吴孝松), and Ning Kang(康宁). Finite superconducting square wire-network based on two-dimensional crystalline Mo₂C[J]. 中国物理B, 2022, 31(9): 97404-097404.
[8]	Jianing Dong(董佳宁), Yang Xiang(向阳), Hong Liu(刘洪), and Suyang Qin(秦苏洋). Effect of pressure evolution on the formation enhancement in dual interacting vortex rings[J]. 中国物理B, 2022, 31(8): 84701-084701.
[9]	Jin-Hao Zhang(张津浩), Biao-Hui Li(李彪辉), Yu-Fei Wang(王宇飞), and Nan Jiang(姜楠). Effects of single synthetic jet on turbulent boundary layer[J]. 中国物理B, 2022, 31(7): 74702-074702.
[10]	Hao Zhu(朱浩), Shou-Gen Yin(印寿根), and Wu-Ming Liu(刘伍明). Vortex chains induced by anisotropic spin-orbit coupling and magnetic field in spin-2 Bose-Einstein condensates[J]. 中国物理B, 2022, 31(6): 60305-060305.
[11]	Hao Zhu(朱浩), Shou-Gen Yin(印寿根), and Wu-Ming Liu(刘伍明). Manipulating vortices in F=2 Bose-Einstein condensates through magnetic field and spin-orbit coupling[J]. 中国物理B, 2022, 31(4): 40306-040306.
[12]	Hao Zhou(周昊), Lei Wang(汪雷), Zhang-Feng Huang(黄章峰), and Jing-Zhi Ren(任晶志). Shedding vortex simulation method based on viscous compensation technology research[J]. 中国物理B, 2022, 31(4): 44702-044702.
[13]	Bing Yan(严兵), Bo Chen(陈波), Zerui Peng(彭泽瑞), and Yong-Liang Xiong(熊永亮). Particle captured by a field-modulating vortex through dielectrophoresis force[J]. 中国物理B, 2022, 31(3): 34703-034703.
[14]	Gepu Guo(郭各朴), Xinjia Li(李昕珈), Qingdong Wang(王青东), Yuzhi Li(李禹志), Qingyu Ma(马青玉), Juan Tu(屠娟), and Dong Zhang(章东). Beam alignments based on the spectrum decomposition of orbital angular momentums for acoustic-vortex communications[J]. 中国物理B, 2022, 31(12): 124302-124302.
[15]	Hasnain Mehdi Jafri, Jing Wang(王静), Xiao-Ming Shi(施小明), De-Shan Liang(梁德山), and Hou-Bing Huang(黄厚兵). Designing current-strain-assisted superconductor-ferromagnet multi-bit memories[J]. 中国物理B, 2022, 31(11): 118501-118501.