Bose-Einstein Condensates with Spin-Orbit Interaction

Abstract

Motivated by recent experiments carried out by Spielman's group at NIST, we study a general scheme for generating families of gauge fields, spanning the scalar, spin-orbit, and non-Abelian regimes. The NIST experiments, which impart momentum to bosons while changing their spin state, can in principle realize all these. In the spin-orbit regime, we show that a Bose gas is a spinor condensate made up of two non-orthogonal dressed spin states carrying different momenta. As a result, its density shows a stripe structure with a contrast proportional to the overlap of the dressed states, which can be made very pronounced by adjusting the experimental parameters.

Multidimensional Josephson vortices in spin-orbit-coupled Bose-Einstein condensates: Snake instability and decay through vortex dipoles

“…This dynamical regime is denominated plane-wave (PW) phase, and it is also characterized by the population imbalance of the ground state. More strikingly, when the interaction increases, the system enters the stripe phase, which shows density modulations as a result of the interference created by the occupation of the two momentum states [7,37].…”

A stripe phase with supersolid properties in spin–orbit-coupled Bose–Einstein condensates

“…The vertical width of the stripe phase in Fig. 3a depends on the miscibility of the two spin components 6,20 . However, as observed in ref.…”

“…With ultracold atoms, idealized Hamiltonians can be experimentally realized and studied. Starting from superfluid Bose-Einstein condensates (BECs), several forms of supersolid have been predicted by adding interactions in the form of dipolar interactions 12,13 , Rydberg interactions 14 , superradiant Rayleigh scattering 15 , nearest-neighbour interaction in lattices 16 and spin-orbit interactions [5][6][7][8] . Several of these proposals lead to solidity along a single spatial direction maintaining their gaseous or liquid-like properties along the other directions i .…”

“…In the present case, the periodicity is given by the wavelength and geometry of the Raman beams. It is then further modified by the spin gap parameter  and the interatomic interactions 5,6 to be 2d /   2 1/ F   , where F = (2Er + n(g+ iii Since the tunnel coupling along the superlattice direction is weak (about 1 kHz) it seems possible that the alignment of moving stripe patterns is more sensitive to perturbations than for stationary stripes and leads to a reduced Debye-Waller factor for moving stripes. g))/4.…”

Moving obstacle potential in a spin-orbit-coupled Bose-Einstein condensate

“…In contrast, we directly solve the GrossPitaevskii (GP) equation with SOC and investigate the dynamical effects of the moving obstacle potential on the SO-coupled condensate. Most theoretical studies on BEC with Rashba SOC have focused on the static properties of the condensate [16][17][18][19][20][21][22], and there have only been a few studies on dynamics [23][24][25][26].…”