Photon-assisted tunneling resonantly controlling spin current of a spin-orbit-coupled atom in a toroidal trap

Z Li, X Hu, ZY Zeng, AX Chen, X Luo - arXiv preprint arXiv:2406.16002, 2024 - arxiv.org
Z Li, X Hu, ZY Zeng, AX Chen, X Luo
arXiv preprint arXiv:2406.16002, 2024arxiv.org
The periodic flashing potential has proven to be a powerful tool for investigating directed
atomic currents. By applying the flashing ring-shaped potential to spin-orbit (SO) coupled,
noninteracting Bose-Einstein condensate (BEC) systems, through photon-assisted tunneling
(resonance) techniques, we demonstrate the generation of tunable alternating (AC) spin and
atomic mass currents that can be precisely controlled in terms of direction and strength. The
underlying mechanism behind this phenomenon is that the flashing potential supplies …
The periodic flashing potential has proven to be a powerful tool for investigating directed atomic currents. By applying the flashing ring-shaped potential to spin-orbit (SO) coupled, noninteracting Bose-Einstein condensate (BEC) systems, through photon-assisted tunneling (resonance) techniques, we demonstrate the generation of tunable alternating (AC) spin and atomic mass currents that can be precisely controlled in terms of direction and strength. The underlying mechanism behind this phenomenon is that the flashing potential supplies enough photons to induce Rabi oscillations and provides momentum transfer for spin and atomic transport. As the single-particle ground state of the unperturbed SO-coupled BEC depends on the Raman coupling strength, we demonstrate how to generate and control AC spin currents in the cases where the initial state resides in a single-well or double-well phase. In particular, we realize and explain the mechanism of generating a net AC spin current without mass current through single-photon resonance processes. It is shown that these interesting resonance phenomena can be analytically described only by the simple three-level model, which creates the possibility of transparent controls of spin dynamics.
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