Finite-Momentum Dimer Bound State in Spin-Orbit Coupled Fermi Gas

Abstract

We investigate the two-body properties of a spin-1/2 Fermi gas subject to a spin-orbit coupling induced by laser fields. When an attractive s-wave interaction between unlike spins is present, the system may form a dimer bound state. Surprisingly, in the presence of a Zeeman field along the direction of the spin-orbit coupling, the bound state obtains finite center-of-mass mechanical momentum, whereas under the same condition but in the absence of the two-body interaction, the system has zero total momentum. This unusual result can be regarded as a consequence of the broken Galilean invariance by the spin-orbit coupling. Such a finite-momentum bound state will have profound effects on the many-body properties of the system.

3 figures, 6 pages, published version

References in corpus (6)

• Spin-Injection Spectroscopy of a Spin-Orbit Coupled Fermi Gas
• Spin-Orbit Coupled Spinor Bose-Einstein Condensates
• A Bose-Einstein Condensate in a Uniform Light-induced Vector Potential
• BCS-BEC crossover induced by a synthetic non-Abelian gauge field
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Cited by in corpus (15)

• Degenerate Quantum Gases with Spin-Orbit Coupling
• Effects of Spin-Orbit Coupling on Jaynes-Cummings and Tavis-Cummings Models
• Three-component Ultracold Fermi Gases with Spin-Orbit Coupling
• Gapless topological Fulde-Ferrell superfluidity induced by in-plane Zeeman field
• Bloch oscillations of spin-orbit-coupled cold atoms in an optical lattice and spin current generation
• Spin-orbital-angular-momentum-coupled quantum gases
• Superfluid density and Berezinskii-Kosterlitz-Thouless transition of a spin-orbit coupled Fulde-Ferrell superfluid
• Three-dimensional spin-orbit coupled Fermi gases: Fulde-Ferrell pairing, Majorana fermions, Weyl fermions and gapless topological superfluidity
• Spin-orbit-coupled topological Fulde-Ferrell states of fermions in a harmonic trap
• Center-of-mass-momentum-dependent interaction between ultracold atoms
• Thermodynamic Properties of Rashba Spin-Orbit-Coupled Fermi Gas
• Synthetic-gauge-field-induced resonances and Fulde-Ferrell-Larkin-Ovchinnikov states in a one-dimensional optical lattice
• BCS-BEC crossover and quantum phase transition in an ultracold Fermi gas under spin-orbit coupling
• Molecular state in a spin-orbital-angular-momentum coupled Fermi gas
• Triplet character of 2D-fermion dimers arising from $s$-wave attraction via spin-orbit coupling and Zeeman splitting