Please wait a minute...
Chin. Phys. B, 2019, Vol. 28(7): 070501    DOI: 10.1088/1674-1056/28/7/070501
GENERAL Prev   Next  

Impurity-induced Shiba bound state in the BCS-BEC crossover regime of two-dimensional Fermi superfluid

Siqi Shao(邵思齐)1,2, Kezhao Zhou(周可召)3, Zhidong Zhang(张志东)1,2
1 Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
2 School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China;
3 Department of Physics, College of Science, Hunan University of Technology, Zhuzhou 412007, China
Abstract  

For a two-dimensional ultra-cold Fermi superfluid with an effective static magnetic impurity, we theoretically investigated the variation of the Yu-Shiba-Rusinov (YSR) bound state in the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation (BEC) crossover regime. Within the framework of mean-field theory, analytical results of the YSR bound state energy were obtained as a function of the interaction parameters. First, when the background Fermi superfluid system stays in the weakly interacting BCS regime, we found that the YSR bound state energy is linearly dependent on the gap parameter with its coefficient slightly different from previous results. Second, we discovered re-entrance phenomena for the YSR state and an upper bound of the strength of the interaction between the paired atoms. By carefully analyzing the bound state energy as a function of the interaction parameters, we obtained a phase diagram showing the existence of the YSR state. Finally, we concluded that the re-entrance phenomena and the critical point can be easily experimentally detected through measurement of radio-frequency spectroscopy and density of states using current experimental techniques.

Keywords:  ultra-cold quantum gases      BCS-BEC crossover      magnetic impurity      Yu-Shiba-Rusinov (YSR) state  
Received:  26 January 2019      Revised:  15 April 2019      Accepted manuscript online: 
PACS:  05.30.Fk (Fermion systems and electron gas)  
  37.10.Jk (Atoms in optical lattices)  
  03.75.Hh (Static properties of condensates; thermodynamical, statistical, and structural properties)  
Fund: 

Project supported by the National Key R&D Program of China (Grant No. 2017YFA0206302).

Corresponding Authors:  Kezhao Zhou     E-mail:  kezhaozhou@gmail.com

Cite this article: 

Siqi Shao(邵思齐), Kezhao Zhou(周可召), Zhidong Zhang(张志东) Impurity-induced Shiba bound state in the BCS-BEC crossover regime of two-dimensional Fermi superfluid 2019 Chin. Phys. B 28 070501

[33] Bausmerth I, Recati A and Stringari S 2009 Phys. Rev. A 79 043622
[1] Bloch I, Dalibard J and Zwerger W 2008 Rev. Mod. Phys. 80 885
[34] Vernier E, Pekker D, Zwierlein M W and Demler E 2011 Phys. Rev. A 83 033619
[2] Gross C and Bloch I 2017 Science 357 995
[35] Yan Z B, Yang X S, Sun L and Wan S L 2012 Euro. Phys. J. B 85 417
[3] Liu X J, Hu H and Pu H 2015 Chin. Phys. B 24 50502
[36] Hu H, Jiang L, Pu H, Chen Y and Liu X J 2013 Phys. Rev. Lett. 110 020401
[4] Wang Z Z, Wu Y D, Du H J and Jing X L 2016 Chin. Phys. B 25 77303
[37] Jiang L, Baksmaty L O, Hu H, Chen Y and Pu H 2011 Phys. Rev. A 83 061604
[5] O'Hara K M, Hemmer S L, Gehm M E, Granade S R and Thomas J E 2002 Science 298 2179
[38] Hirschfeld P J, Vollhard D and Wölfle P 1986 Solid State Commun. 59 111
[6] Bourdel T, Cubizolles J, Khaykovich L, Magalhaes K, Kokkelmans S, Shlyapnikov G and Salomon C 2003 Phys. Rev. Lett. 91 020402
[39] Randeria M, Duan J M and Shieh L Y 1990 Phys. Rev. B 41 327
[40] Diener R B, Sensarma R and Randeria M 2008 Phys. Rev. A 77 023626
[7] Leggett A J 1980 Journal de Physique Colloques 41 C7
[41] de Melo C S, Randeria M and Engelbrecht J R 1993 Phys. Rev. Lett. 71 3202
[8] Cheuk L W, Nichols M A, Lawrence K R, Okan M, Zhang H, Khatami E, Trivedi N, Paiva T, Rigol M and Zwierlein M W 2016 Science 353 1260
[9] Boll1 M, Hilker T A, Salomon G, Omran A, Nespolo J, Pollet L, Bloch I and Gross C 2016 Science 353 1257
[42] Chen Q J, Stajic J, Tan S N and Levin K 2005 Phys. Rep. 412 1
[10] Gross C and Bloch I 2017 Science 357 995
[43] Chen Q J, Kosztin I, Jank B and Levin K 1998 Phys. Rev. Lett. 81 4708
[11] Abrikosov A A and Gor'kov L P 1961 Sov. Phys. JETP Lett. 12 1243
[44] Chen Q J and Schrieffer J R 2002 Phys. Rev. B 66 014512
[12] Yu L 1965 Acta Phys. Sin. 21 75 (in Chinese)
[45] He L, Lü H F, Cao G Q, Hu H and Liu X J 2015 Phys. Rev. A 92 023620
[13] Shiba H 1968 Prog. Theor. Phys. 40 435
[14] Shiba H and Soda T 1969 Prog. Theor. Phys. 41 25
[15] Rusinov A I 1969 Sov. Phys. JETP Lett. 9 85
[16] Rusinov A I 1969 Sov. Phys. JETP Lett. 29 1101
[17] Fischer o, Kugler M, Maggio-Aprile I, Berthod C and Renner C 2007 Rev. Mod. Phys. 79 353
[18] Pan S H, Hudson E W, Lang K M, Eisaki H, Uchida S and Davis J C 2000 Nature 403 746
[19] Balatsky A V 2000 Nature 403 717
[20] Hoffman J E, McElroy K, Lee D H, Lang K M, Eisaki H, Uchida S and Davis J C 2002 Science 297 1148
[21] Balatsky A V, Vekhter I and Zhu J X 2006 Rev. Mod. Phys. 78 373
[22] Kaladzhyan V, Bena C and Simon P 2016 Phys. Rev. B 93 214514
[23] Nadj-Perge S, Drozdov I K, Bernevig B A and Yazdani A 2013 Phys. Rev. B 88 020407
[24] Kim Y, Cheng M, Bauer B, Lutchyn R M and Sarma S D 2014 Phys. Rev. B 90 060401
[25] Nadj-Perge S, Drozdov I K, Li J, Chen H, Jeon S, Seo J, MacDonald A H, Bernevig B A and Yazdani A 2014 Science 346 602
[26] Nayak C, Simon S H, Stern A, Freedman M and Sarma S D 2008 Rev. Mod. Phys. 80 1083
[27] Qi X L and Zhang S C 2011 Rev. Mod. Phys. 83 1057
[28] Sau J D and Demler E 2013 Phys. Rev. B 88 064506
[29] Liu D E, Rossi E and Lutchyn R M 2018 Phys. Rev. B 97 161408
[30] Modugno G 2010 Rep. Prog. Phys. 73 102401
[31] Zipkes C, Palzer S, Sias C and Köhl M 2010 Nature 464 388
[32] Targońska K and Sacha K 2010 Phys. Rev. A 82 033601
[33] Bausmerth I, Recati A and Stringari S 2009 Phys. Rev. A 79 043622
[34] Vernier E, Pekker D, Zwierlein M W and Demler E 2011 Phys. Rev. A 83 033619
[35] Yan Z B, Yang X S, Sun L and Wan S L 2012 Euro. Phys. J. B 85 417
[36] Hu H, Jiang L, Pu H, Chen Y and Liu X J 2013 Phys. Rev. Lett. 110 020401
[37] Jiang L, Baksmaty L O, Hu H, Chen Y and Pu H 2011 Phys. Rev. A 83 061604
[38] Hirschfeld P J, Vollhard D and Wölfle P 1986 Solid State Commun. 59 111
[39] Randeria M, Duan J M and Shieh L Y 1990 Phys. Rev. B 41 327
[40] Diener R B, Sensarma R and Randeria M 2008 Phys. Rev. A 77 023626
[41] de Melo C S, Randeria M and Engelbrecht J R 1993 Phys. Rev. Lett. 71 3202
[42] Chen Q J, Stajic J, Tan S N and Levin K 2005 Phys. Rep. 412 1
[43] Chen Q J, Kosztin I, Jank B and Levin K 1998 Phys. Rev. Lett. 81 4708
[44] Chen Q J and Schrieffer J R 2002 Phys. Rev. B 66 014512
[45] He L, Lü H F, Cao G Q, Hu H and Liu X J 2015 Phys. Rev. A 92 023620
[1] 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). Chin. Phys. B, 2016, 25(11): 110306.
[2] Spin pumping through magnetic impurity effect
Deng Wei-Yin (邓伟胤), Sheng Li (盛利), Xing Ding-Yu (邢定钰). Chin. Phys. B, 2015, 24(8): 087202.
[3] First-principles study on nonlocal ferromagnetism in (Cu, N)-codoped ZnO
Qin Guo-Ping (秦国平), Wang Xin-Qiang (王新强), Zheng Ji (郑继), Kong Chun-Yang (孔春阳), Ruan Hai-Bo (阮海波), Li Wan-Jun (李万俊), Zhao Yong-Hong (赵永红), Meng Xiang-Dan (孟祥丹). Chin. Phys. B, 2013, 22(5): 057101.
[4] Thermoelectric transport through a quantum dot with a magnetic impurity
Yu Zhen (于震), Guo Yu (郭宇), Zheng Jun (郑军), Chi Feng (迟锋). Chin. Phys. B, 2013, 22(11): 117303.
[5] Spin-polarized transport through a double Aharonov-Bohm ring in the presence of magnetic impurity
Gao Ying-Fang (高迎芳), Zhang Yong-Ping (张永平), Liang Jiu-Qing (梁九卿). Chin. Phys. B, 2005, 14(1): 196-200.
No Suggested Reading articles found!