Spin-Orbit-Coupled Dipolar Bose-Einstein Condensates

State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190, China.
Physical Review Letters (Impact Factor: 7.51). 03/2012; 108(12):125301. DOI: 10.1103/PhysRevLett.108.125301
Source: PubMed

ABSTRACT We propose an experimental scheme to create spin-orbit coupling in spin-3 Cr atoms using Raman processes. By employing the linear Zeeman effect and optical Stark shift, two spin states within the ground electronic manifold are selected, which results in a pseudospin-1/2 model. We further study the ground state structures of a spin-orbit-coupled Cr condensate. We show that, in addition to the stripe structures induced by the spin-orbit coupling, the magnetic dipole-dipole interaction gives rise to the vortex phase, in which a spontaneous spin vortex is formed.

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    • "Thus we will present our results on ground states and dynamics of SO-coupled BECs based on the CGPEs (1.10). We remark that our methods and results are still valid for other theoretical models for SO-coupled BECs in the literatures [28] [16] [32] [13] [18]. For the CGPEs (1.10), when k 0 = 0, i.e., a two-component BEC without SO coupling and without/with Raman coupling corresponding to Ω = 0/Ω = 0, ground state structures and dynamical properties have been studied theoretically in the literature [4] [11] [24] [5] [26]. "
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    ABSTRACT: We study analytically and asymptotically as well as numerically ground states and dynamics of two-component spin-orbit-coupled Bose-Einstein condensates (BECs) modeled by the coupled Gross-Pitaevskii equations (CGPEs). In fact, due to the appearance of the spin-orbit (SO) coupling in the two-component BEC with a Raman coupling, the ground state structures and dynamical properties become very rich and complicated. For the ground states, we establish the existence and non-existence results under different parameter regimes, and obtain their limiting behaviors and/or structures with different combinations of the SO and Raman coupling strengths. For the dynamics, we show that the motion of the center-of-mass is either non-periodic or with different frequency to the trapping frequency when the external trapping potential is taken as harmonic and the initial data is chosen as a stationary state (e.g. ground state) with a shift, which is completely different from the case of a two-component BEC without the SO coupling, and obtain the semiclassical limit of the CGPEs in the linear case via the Wigner transform method. Efficient and accurate numerical methods are proposed for computing the ground states and dynamics, especially for the case of box potentials. Numerical results are reported to demonstrate the efficiency and accuracy of the numerical methods and show the rich phenomenon in the SO-coupled BECs.
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