针对关阱里德伯门的运动重聚焦
Motional refocusing for trap-off Rydberg gates
AI总结：
该研究开发了一种仅通过可编程捕获光强度切换的运动重聚焦协议，可消除关阱里德伯门的释放-再捕获循环加热，抑制剩余加热并实现无加热的中性原子门。
AI中文摘要：
光镊阵列中的里德伯纠缠门通常在关闭捕获光的情况下执行，因此每个门都包含一个释放-再捕获循环，这会加热原子运动并最终限制电路深度。我们开发了一种运动重聚焦协议，仅通过可编程的捕获光强度切换，在简谐近似下精确消除这种加热。该协议为每个匹配的简谐模式闭合了释放-再捕获循环，使任意运动布居和相干性精确恢复到静态阱下的常规演化状态。我们针对任意捕获深度推导出了闭式恢复序列，并证明在实验相关范围内，该序列是受限阱强度下唯一的全局时间最优解。随后，我们将简谐理论扩展到两个方向：第一，构建了精确的等强度恢复序列，可同时重聚焦多个非简并简谐模式，包括径向-轴向模式和完全各向异性的三维阱；第二，推导了复合序列，通过抵消四次非谐性诱导的所有一阶运动跃迁，抑制弱非谐阱的主导非谐修正，将剩余加热定律从$U_0^{-2}$改变为$U_0^{-4}$。在现实高斯光镊中的波包模拟验证了该解析理论，并量化了非谐性、有限切换斜坡、阱椭圆度和控制误差的剩余效应。将该协议应用于代表性的铯里德伯门，可将主导的再捕获加热抑制到非谐本底，并防止相关运动多普勒贡献随电路深度增加。该框架为仅利用阱强度调制实现无加热关阱中性原子门提供了实用途径。
英文摘要：
Rydberg entangling gates in optical-tweezer arrays are commonly executed with the trapping light switched off, so every gate contains a release--and--recapture cycle that heats the atomic motion and can ultimately limit circuit depth. We develop a motional refocusing protocol that exactly removes this heating in the harmonic approximation using only programmable intensity switching of the trapping light. The protocol closes the release--and--recapture cycle for every matched harmonic mode, returning arbitrary motional populations and coherences exactly up to ordinary evolution under the static trap. We derive the recovery sequence in closed form for arbitrary catch depth and prove that, within the experimentally relevant regime, it is the unique globally time-optimal solution under bounded trap intensity. The harmonic theory is then extended in two directions. First, we construct exact common-intensity recovery sequences that simultaneously refocus several nondegenerate harmonic modes, including radial--axial and fully anisotropic three-dimensional traps. Second, we derive a composite sequence that suppresses the leading anharmonic correction of weakly anharmonic traps by canceling all first-order motional transitions induced by the quartic anharmonicity, changing the residual heating law from $U_0^{-2}$ to $U_0^{-4}$. Wave-packet simulations in realistic Gaussian tweezers validate the analytic theory and quantify the residual effects of anharmonicity, finite switching ramps, trap ellipticity, and control errors. Applied to representative cesium Rydberg gates, the protocol suppresses the dominant recapture heating to the anharmonic floor and prevents the associated motional Doppler contribution from increasing with circuit depth. The resulting framework provides a practical route toward heating-free trap-off neutral-atom gates using only trap-intensity modulation.
