| ATOMIC AND MOLECULAR PHYSICS |
|
|
|
|
Unusual Destruction and Enhancement of Superfluidity of Atomic Fermi Gases by Population Imbalance in a One-Dimensional Optical Lattice |
| Qijin Chen1,2,3**, Jibiao Wang4**, Lin Sun2, Yi Yu5 |
1Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315
2Department of Physics and Zhejiang Institute of Modern Physics, Zhejiang University, Hangzhou 310027
3Synergetic Innovation Center of Quantum Information and Quantum Physics, Hefei 230026
4Laboratory of Quantum Engineering and Quantum Metrology, School of Physics and Astronomy, Sun Yat-Sen University (Zhuhai Campus), Zhuhai 519082
5College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014
|
|
| Cite this article: |
|
Qijin Chen, Jibiao Wang, Lin Sun et al 2020 Chin. Phys. Lett. 37 053702 |
|
|
|
|
Abstract We study the superfluid behavior of a population imbalanced ultracold atomic Fermi gases with a short range attractive interaction in a one-dimensional (1D) optical lattice, using a pairing fluctuation theory. We show that, besides widespread pseudogap phenomena and intermediate temperature superfluidity, the superfluid phase is readily destroyed except in a limited region of the parameter space. We find a new mechanism for pair hopping, assisted by the excessive majority fermions, in the presence of continuum-lattice mixing, which leads to an unusual constant Bose-Einstein condensate (BEC) asymptote for $T_{\rm c}$ that is independent of pairing strength. In result, on the BEC side of unitarity, superfluidity, when it exists, may be strongly enhanced by population imbalance.
|
|
Received: 31 March 2020
Published: 20 April 2020
|
|
| PACS: |
37.10.Jk
|
(Atoms in optical lattices)
|
| |
67.85.-d
|
(Ultracold gases, trapped gases)
|
| |
74.25.Dw
|
(Superconductivity phase diagrams)
|
| |
03.75.Ss
|
(Degenerate Fermi gases)
|
|
|
| Fund: Supported by the National Natural Science Foundation of China (Grant Nos. 11774309 and 11674283) and the Natural Science Foundation of Zhejiang Province of China (Grant No. LZ13A040001). |
|
|
|
| [1] | Chen Q J, Stajic J, Tan S N and Levin K 2005 Phys. Rep. 412 1 | | [2] | Bloch I, Dalibard J and Zwerger W 2008 Rev. Mod. Phys. 80 885 | | [3] | Zwierlein M W, Schirotzek A, Schunck C H and Ketterle W 2006 Science 311 492 | | [4] | Partridge G B, Li W, Kamar R I, Liao Y A and Hulet R G 2006 Science 311 503 | | [5] | Chen Q J, He Y, Chien C C and Levin K 2006 Phys. Rev. A 74 063603 | | [6] | Radzihovsky L and Sheehy D E 2010 Rep. Prog. Phys. 73 076501 | | [7] | Yi W and Duan L M 2006 Phys. Rev. A 73 031604(R) | | [8] | Pao C H, Wu S T and Yip S K 2006 Phys. Rev. B 73 132506 | | [9] | Forbes M M, Gubankova E, Liu W V and Wilczek F 2005 Phys. Rev. Lett. 94 017001 | | [10] | Chien C C, Chen Q J, He Y and Levin K 2006 Phys. Rev. Lett. 97 090402 | | [11] | Chen Q J, He Y, Chien C C and Levin K 2007 Phys. Rev. B 75 014521 | | [12] | Chen Q J, Kosztin I, Jankó B and Levin K 1999 Phys. Rev. B 59 7083 | | [13] | Hofstetter W, Cirac J I, Zoller P, Demler E and Lukin M D 2002 Phys. Rev. Lett. 89 220407 | | [14] | Bloch I 2005 Nat. Phys. 1 23 | | [15] | Köhl M, Moritz H, Stöferle T, Günter K and Esslinger T 2005 Phys. Rev. Lett. 94 080403 | | [16] | Cazalilla M A, Ho A F and Giamarchi T 2005 Phys. Rev. Lett. 95 226402 | | [17] | Orso G, Pitaevskii L P, Stringari S and Wouters M 2005 Phys. Rev. Lett. 95 060402 | | [18] | Koponen T, Kinnunen J, Martikainen J P, Jensen L M and Törmä P 2006 New J. Phys. 8 179 | | [19] | Chien C C, He Y, Chen Q J and Levin K 2008 Phys. Rev. A 77 011601 | | [20] | Giorgini S, Pitaevskii L P and Stringari S 2008 Rev. Mod. Phys. 80 1215 | | [21] | Cai Z, Wang Y and Wu C 2011 Phys. Rev. A 83 063621 | | [22] | Cichy A and Micnas R 2014 Ann. Phys. 347 207 | | [23] | Ong W, Cheng C, Arakelyan I and Thomas J E 2015 Phys. Rev. Lett. 114 110403 | | [24] | Kangara J, Cheng C, Pegahan S, Arakelyan I and Thomas J E 2018 Phys. Rev. Lett. 120 083203 | | [25] | An optical lattice in a theory paper in the literature often refers to a pure lattice in the context of a Hubbard model. Namely, a 1DOL means a simple 1D atomic chain. This is different from the 1DOL we study here. | | [26] | Chen Q J, Kosztin I, Jankó B and Levin K 1998 Phys. Rev. Lett. 81 4708 | | [27] | Chen Q J and Wang J B 2014 Front. Phys. 9 539 | | [28] | Yu Y and Chen Q J 2010 Physica C 470 S900 | | [29] | Kinnunen J, Rodriguez M and Törmä P 2004 Science 305 1131 | | [30] | Lin G D, Yi W and Duan L M 2006 Phys. Rev. A 74 031604(R) | | [31] | He L, Huang X G, Hu H and Liu X J 2013 Phys. Rev. A 87 053616 | | [32] | Considering changing $t$ and $d$, here we define $k_{\rm F}$ and $T_{\rm F}$ as given by a homogeneous, unpolarized, noninteracting Fermi gas with the same total number density $n$ in 3D. | | [33] | Nozières P and Schmitt-Rink S 1985 J. Low Temp. Phys. 59 195 | | [34] | Note that Eq. (5) depends on the product $a_0\mathit{\Delta}^2$ and the ratio $a_0/a_1$, but not on $\mathit{\Delta}$ separately. | | [35] | Che Y M, Wang J B and Chen Q J 2016 Phys. Rev. A 93 063611 | | [36] | Berezinskii V L 1972 Sov. Phys.-JETP 34 610 | | [37] | Kosterlitz J M and Thouless D J 1973 J. Phys. C 6 1181 |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
