TY - JOUR
T1 - Competing superfluid orders in spin-orbit-coupled fermionic cold-atom optical lattices
AU - Xu, Yong
AU - Qu, Chunlei
AU - Gong, Ming
AU - Zhang, Chuanwei
PY - 2014/1/10
Y1 - 2014/1/10
N2 - The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase, a superconducting state with nonzero total momentum Cooper pairs in a large magnetic field, was first predicted about 50 years ago and has since become an important concept in many branches of physics. Despite an intensive search in various materials, unambiguous experimental evidence for the FFLO phase is still lacking in experiments. In this paper we show that both Fulde-Ferrell (FF) (a uniform order parameter with a plane-wave phase) and Larkin-Ovchinnikov (LO) phases (a spatially varying order parameter amplitude) can be observed using fermionic cold atoms in spin-orbit-coupled optical lattices. The increasing spin-orbit coupling enhances the FF phase over the LO phase. The coexistence of superfluid and magnetic orders is also found in the normal BCS phase. The pairing mechanism for different phases is understood by visualizing superfluid pairing densities in different spin-orbit bands. The possibility of observing similar physics using spin-orbit-coupled superconducting ultrathin films is also discussed.
AB - The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase, a superconducting state with nonzero total momentum Cooper pairs in a large magnetic field, was first predicted about 50 years ago and has since become an important concept in many branches of physics. Despite an intensive search in various materials, unambiguous experimental evidence for the FFLO phase is still lacking in experiments. In this paper we show that both Fulde-Ferrell (FF) (a uniform order parameter with a plane-wave phase) and Larkin-Ovchinnikov (LO) phases (a spatially varying order parameter amplitude) can be observed using fermionic cold atoms in spin-orbit-coupled optical lattices. The increasing spin-orbit coupling enhances the FF phase over the LO phase. The coexistence of superfluid and magnetic orders is also found in the normal BCS phase. The pairing mechanism for different phases is understood by visualizing superfluid pairing densities in different spin-orbit bands. The possibility of observing similar physics using spin-orbit-coupled superconducting ultrathin films is also discussed.
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U2 - 10.1103/PhysRevA.89.013607
DO - 10.1103/PhysRevA.89.013607
M3 - Article
AN - SCOPUS:84892493790
SN - 1050-2947
VL - 89
JO - Physical Review A - Atomic, Molecular, and Optical Physics
JF - Physical Review A - Atomic, Molecular, and Optical Physics
IS - 1
M1 - 013607
ER -