Polarization of a quasi two-dimensional repulsive Fermi gas with Rashba spin-orbit coupling: a variational study

Abstract

Motivated by the remarkable experimental control of synthetic gauge fields in ultracold atomic systems, we investigate the effect of an artificial Rashba spin-orbit coupling on the spin polarization of a two-dimensional repulsive Fermi gas. By using a variational many-body wavefunction, based on a suitable spinorial structure, we find that the polarization properties of the system are indeed controlled by the interplay between spin-orbit coupling and repulsive interaction. In particular, two main effects are found: 1) The Rashba coupling determines a gradual increase of the degree of polarization beyond the critical repulsive interaction strength, at variance with conventional 2D Stoner instability. 2) The critical interaction strength, above which finite polarization is developed, shows a dependence on the Rashba coupling, i.e. it is enhanced in case the Rashba coupling exceeds a critical value. A simple analytic expression for the critical interaction strength is further derived in the context of our variational formulation, which allows for a straightforward and insightful analysis of the present problem.

7 pages, 3 figures

References in corpus (12)

• Spin-Injection Spectroscopy of a Spin-Orbit Coupled Fermi Gas
• Bright solitons in spin-orbit-coupled Bose-Einstein condensates
• Effect of Induced Spin-Orbit Coupling for Atoms via Laser Fields
• Anisotropic dynamics of a spin-orbit coupled Bose-Einstein condensate
• Generalized Rashba spin-orbit coupling for cold atoms
• BCS-BEC crossover induced by a synthetic non-Abelian gauge field
• Soliton Magnetization Dynamics in Spin-Orbit Coupled Bose-Einstein Condensates
• Itinerant ferromagnetism in an atomic Fermi gas: Influence of population imbalance
• Stationary States of Trapped Spin-Orbit-Coupled Bose-Einstein Condensates
• A two-dimensional Fermi liquid with attractive interactions
• Ground State Properties of Spin-Orbit Coupled Bose Gases for Arbitrary Interactions
• Zero-Temperature Equation of State and Phase Diagram of Repulsive Fermionic Mixtures

Cited by in corpus (2)

• A generalized Stoner criterion and versatile spin ordering in two-dimensional spin-orbit coupled electron systems
• Interplay between Rashba spin-orbit coupling and adiabatic rotation in a two-dimensional Fermi gas