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arXiv · 2206.04894

Coherent transfer of the transverse momentum of an optical vortex beam to the motion of a single trapped ion

Abstract

We demonstrate the excitation, using a structured light beam carrying orbital angular momentum, of the center of mass motion of a single atom in the transverse direction to the beam's propagation. This interaction is achieved with a vortex beam carrying one unit of orbital angular momentum and one unit of spin/polarization angular momentum. Using a singly charged $^{40}$Ca$^+$ ion, cooled near the ground state of motion in the 3D harmonic potential of a Paul trap, we probe the narrow S$_{1/2}$ to D$_{5/2}$ transition near $729\,\mathrm{nm}$ on its motional sidebands to quantify the momentum transfer. Exchange of quanta in the perpendicular direction to the beam's wave vector $\mathbf{k}$ is observed in case of the vortex shaped beam, in strong contrast to the absence of this spin-motion coupling for the case of a Gaussian beam. We characterize the coherent interaction by an effective transverse Lamb-Dicke factor $\eta^\mathrm{exp}_{\perp}=0.0062(5)$ which is in agreement with our theoretical prediction $\eta^\mathrm{theo}_{\perp}=0.0057(1)$

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Felix Stopp, Maurizio Verde, Milton Katz, Martin Drechsler, Christian T. Schmiegelow, Ferdinand Schmidt-Kaler. 2022-06-10. Coherent transfer of the transverse momentum of an optical vortex beam to the motion of a single trapped ion. https://doi.org/10.1103/physrevlett.129.263603

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