论文标题
用于量子信息处理的可调横向自旋运动耦合
Tunable transverse spin-motion coupling for quantum information processing
论文作者
论文摘要
在被困的离子库仑晶体中，原子量子盘（“旋转”）和集体运动之间的激光控制的纠缠需要有条件的动量从激光转移。由于自旋依赖性力是从自旋相互作用中的空间梯度得出的，因此该力通常是纵向的 - 平行于平均激光$ k $ vector（或两个梁的$ k $ - vector差异），这构成了可访问的自旋运动耦合的方向和相对大小。在这里，我们展示了如何由于其横向剖面中的梯度，也可以将动量垂直于单个激光束传递。通过通过光束塑形控制离子位置的横向梯度，可以调整边带和载体的相对强度，以优化所需的相互作用并抑制不希望的，抗谐振的效果，从而可以降低门的保真度。我们还讨论了这种效果如何在最近的实验中扮演着未引人注目的角色。
Laser-controlled entanglement between atomic qubits (`spins') and collective motion in trapped ion Coulomb crystals requires conditional momentum transfer from the laser. Since the spin-dependent force is derived from a spatial gradient in the spin-light interaction, this force is typically longitudinal -- parallel and proportional to the average laser $k$-vector (or two beams' $k$-vector difference), which constrains both the direction and relative magnitude of the accessible spin-motion coupling. Here, we show how momentum can also be transferred perpendicular to a single laser beam due to the gradient in its transverse profile. By controlling the transverse gradient at the position of the ion through beam shaping, the relative strength of the sidebands and carrier can be tuned to optimize the desired interaction and suppress undesired, off-resonant effects that can degrade gate fidelity. We also discuss how this effect may already be playing an unappreciated role in recent experiments.
