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Inducing vortices in a Bose-Einstein condensate using light beams with orbital angular momentum

Waseem Bakr, Jonathon I. Gillen, Amy Peng +2 more

Bulletin of the American Physical SocietyMay 28, 20080 citations

Gauge-potential-induced vortices in spin-1 Bose–Einstein condensates with spin–orbit coupling

Jingjing Jin, Hui Guo, Suying Zhang +1 more

Annals of PhysicsSep 19, 20195 citations

Bose-Einstein condensates with spin and orbital angular momentum coupling

Kuei Sun, Chunlei Qu, Chuanwei Zhang

Bulletin of the American Physical SocietyMar 2, 20150 citations

Spin - orbital angular momentum coupled Bose-Einstein condensate

Chunlei Qu, Kuei Sun, Chuanwei Zhang

Bulletin of the American Physical SocietyMar 6, 20151 citation

Vortex Nucleations in Spinor Bose Condensates under Localized Synthetic Magnetic Fields

L.-R. Liu, Shun‐Chi Wu, T.-W. Liu +5 more

Gauge fields are ubiquitous in modern quantum physics. In superfluids, quantized vortices can be induced by gauge fields. Here we demonstrate the first experimental observation of vortex nucleations in light-dressed spinor Bose-Einstein condensates under radially localized synthetic magnetic fields. The light-induced spin-orbital-angular-momentum coupling creates azimuthal gauge potentials A[over →] for the lowest-energy spinor branch dressed eigenstate. The observation of the atomic wave function in the lowest-energy dressed eigenstate reveals that vortices nucleate from the cloud center of a vortex-free state with canonical momentum p[over →]=0. This is because a large circulating azimuthal velocity field ∝p[over →]-A[over →] at the condensate center results in a dynamically unstable localized excitation that initiates vortex nucleations. Furthermore, the long-time dynamics to reach the ground state stops in a metastable state when |A[over →]| is not sufficiently large. Our observation has reasonable agreement with the time-dependent Gross-Pitaevskii simulations.Gauge fields are ubiquitous in modern quantum physics. In superfluids, quantized vortices can be induced by gauge fields. Here we demonstrate the first experimental observation of vortex nucleations in light-dressed spinor Bose-Einstein condensates under radially localized synthetic magnetic fields. The light-induced spin-orbital-angular-momentum coupling creates azimuthal gauge potentials A[over →] for the lowest-energy spinor branch dressed eigenstate. The observation of the atomic wave function in the lowest-energy dressed eigenstate reveals that vortices nucleate from the cloud center of a vortex-free state with canonical momentum p[over →]=0. This is because a large circulating azimuthal velocity field ∝p[over →]-A[over →] at the condensate center results in a dynamically unstable localized excitation that initiates vortex nucleations. Furthermore, the long-time dynamics to reach the ground state stops in a metastable state when |A[over →]| is not sufficiently large. Our observation has reasonable agreement with the time-dependent Gross-Pitaevskii simulations.

arXiv:2403.17403Physical Review LettersJul 28, 20251 citation

Quantum-fluid q -plates in spinor Bose–Einstein condensates

Netzer Moriya

We propose a reconfigurable way to convert the polarization of light into orbital angular momentum using a spinor Bose–Einstein condensate (BEC). In conventional optics, this conversion is performed by a q -plate, a patterned birefringent element that couples circular polarization (spin angular momentum) to a helical wavefront (orbital angular momentum). Here, we show that an in-plane spin (or nematic) texture in a spinor BEC can play the same role: it imprints a geometric phase that converts incident circularly polarized light into a new orbital-angular-momentum channel set by the texture winding number q . In the low-loss, adiabatic regime, we derive a closed-form mapping for the transmitted field, which yields a quantized selection rule Δ ℓ =2 s q ( s =±1) and a simple back-action law for the reaction torque on the condensate. Notably, the predicted torque vanishes at q =1 in the ideal limit, providing a clear experimental signature of angular-momentum exchange. We analyze robustness to smooth azimuthal distortions and identify breakdown when defects form or loss dominates. Monte Carlo sampling and two-component beam-propagation simulations confirm the predicted conversion efficiency, OAM spectrum, and torque response.We propose a reconfigurable way to convert the polarization of light into orbital angular momentum using a spinor Bose–Einstein condensate (BEC). In conventional optics, this conversion is performed by a q -plate, a patterned birefringent element that couples circular polarization (spin angular momentum) to a helical wavefront (orbital angular momentum). Here, we show that an in-plane spin (or nematic) texture in a spinor BEC can play the same role: it imprints a geometric phase that converts incident circularly polarized light into a new orbital-angular-momentum channel set by the texture winding number q . In the low-loss, adiabatic regime, we derive a closed-form mapping for the transmitted field, which yields a quantized selection rule Δ ℓ =2 s q ( s =±1) and a simple back-action law for the reaction torque on the condensate. Notably, the predicted torque vanishes at q =1 in the ideal limit, providing a clear experimental signature of angular-momentum exchange. We analyze robustness to smooth azimuthal distortions and identify breakdown when defects form or loss dominates. Monte Carlo sampling and two-component beam-propagation simulations confirm the predicted conversion efficiency, OAM spectrum, and torque response.

Journal of the Optical Society of America BMar 25, 20260 citations

Light-induced Azimuthal Gauge Potentials and Spin-orbital-angular-momentum coupling in Bose-Einstein condensates

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