Berezinskii-Kosterlitz-Thouless Phase Transition in 2D Spin-Orbit Coupled Fulde-Ferrell Superfluids

Abstract

The experimental observation of traditional Zeeman-field induced Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluids has been hindered by various challenges, in particular, the requirement of low dimensional systems. In 2D, finite temperature phase fluctuations lead to extremely small Berezinskii-Kosterlitz-Thouless (BKT) transition temperature for FFLO superfluids, raising serious concerns regarding their experimental observability. Recently, it was shown that FFLO superfluids can be realized using a Rashba spin-orbit coupled Fermi gas subject to Zeeman fields, which may also support topological excitations such as Majorana fermions in 2D. Here we address the finite temperature BKT transition issue in this system, which may exhibit gapped, gapless, topological, and gapless topological FF phases. We find a large BKT transition temperature due to large effective superfluid densities, making it possible to observe 2D FF superfluids at finite temperature. In addition, we show that gapless FF superfluids can be stable due to their positive superfluid densities. These findings pave the way for the experimental observation of 2D gapped and gapless FF superfluids and their associated topological excitations at finite temperature.

9 pages, 4 figures, including supplementary materials

References in corpus (9)

• Spin-Injection Spectroscopy of a Spin-Orbit Coupled Fermi Gas
• Non-Abelian Topological Order in S-Wave Superfluids of Ultracold Fermionic Atoms
• $p_x+i{p}_y$ superfluid from s-wave interactions of fermionic cold atoms
• Quasi-one-dimensional polarized Fermi superfluids
• Probing non-Abelian statistics of Majorana fermions in ultracold atomic superfluid
• Unconventional superfluid in a two-dimensional Fermi gas with anisotropic spin-orbit coupling and Zeeman fields
• FFLO state in 1, 2, and 3 dimensional optical lattices combined with a non-uniform background potential
• Effects of spin-orbit coupling on the Berezinskii-Kosterlitz-Thouless transition and the vortex-antivortex structure in two-dimensional Fermi gases
• Gapless topological Fulde-Ferrell superfluidity induced by in-plane Zeeman field

Cited by in corpus (8)

• Spin - orbital-angular-momentum coupling in Bose-Einstein condensates
• Quantum phases of Bose-Einstein condensates with synthetic spin - orbital-angular-momentum coupling
• Topological Fulde-Ferrell Superfluids of a Spin-Orbit Coupled Fermi Gas
• Investigation of the spin-1 honeycomb antiferromagnet BaNi${}_2$V${}_2$O${}_8$ with easy plane anisotropy
• Topological defects of spin-orbit coupled Bose-Einstein condensates in a rotating anharmonic trap
• Effective Hamiltonian with tunable mixed pairing in driven optical lattices
• Kosterlitz-Thouless transition and vortex-antivortex lattice melting in two-dimensional Fermi gases with $p$- or $d$-wave pairing
• $\mathcal{P}\mathcal{T}$-Symmetry Enhanced Berezinskii-Kosterlitz-Thouless Superfluidity