Vortex force in compressible spin-orbit-coupled Bose-Einstein condensates

Abstract

Using a (1+2)-dimensional boson-vortex duality between non-linear electrodynamics and a two-component compressible Bose-Einstein condensate (BEC) with spin-orbit (SO) coupling, we obtain generalised versions of the hydrodynamic continuity and Euler equations where the phase defect and non-defect degrees of freedom enter separately. We obtain the generalised Magnus force on vortices under SO coupling, and associate the linear confinement of vortices due to SO coupling with instanton fluctuations of the dual theory.Keywords: Vortex-boson duality, duality between U (1) gauge theory and XY model, Bose-Einstein condensate, spin-orbit coupling, sine-Gordon equation, multi-valued fields, coherent Rabi coupling Introduction: The recent ground-breaking experimental developments of spin-orbit (SO) coupling in ultracold atomic gases continue to highlight the importance of these highly controllable systems as emulators of condensed matter. For bosons [1,2], this was achieved following the earlier synthetic creation of an artificial magnetic field [3], which makes it possible to create stationary vortices in a non-rotating condensate, but the impact of SO coupling goes deeper. In particular, the dynamics of quantised vortices is affected in a non-trivial way as a result of an additional contribution to the vortex force by the SO and Rabi couplings, which we derive here. We present a hydrodynamic description of SO coupled BECs that directly includes dynamics of the vortex degrees of freedom.

Effect of spin–orbit coupling on tunnelling escape of Bose–Einstein condensate

“…A new kind of Josephson effect-momentum space Josephson effect-has been predicted [33]. It is also reported that SO coupling will lead to rich dynamical phenomena of BEC Josephson vortices [34,35].…”

Spotlighting phase separation in Rashba spin-orbit coupled Bose–Einstein condensates in two dimensions

“…However, most of the studies on SO coupled BECs were primarily centered on the one-dimensional systems and only a few studies were devoted on two-dimensional SO coupled BECs. For instance, the dynamics of vortices, the existence of vortex-antivortex pair, modulation instability in quasi-two-dimensional BEC [38][39][40][41][42][43] are few notable works concerning higher dimensional SO coupled-BEC. One way of controlling the dimensionality of the system is by using a tight optical confinement of the atomic cloud along one or two directions [14][15][16].…”