The precise engineering of quantum states, a basic prerequisite for technologies such as quantum-enhanced sensing or quantum computing, becomes more challenging with increasing dimension of the system Hilbert space. Standard preparation techniques then require a large number of operations or slow adiabatic evolution and give access to only a limited set of states. Here, we use quantum optimal control theory to overcome this problem and derive shaped radio-frequency pulses to experimentally navigate the Stark manifold of a Rydberg atom. We demonstrate that optimal control, beyond improving the fidelity of an existing protocol, also enables us to accurately generate a nonclassical superposition state that cannot be prepared with reasonable fidelity using standard techniques. Optimal control thus substantially enlarges the range of accessible states. Our joint experimental and theoretical work establishes quantum optimal control as a key tool for quantum engineering in complex Hilbert spaces.

中文翻译：

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使用量子最优控制在大型希尔伯特空间中快速导航

量子态的精确工程是诸如量子增强传感或量子计算等技术的基本前提，随着系统希尔伯特空间尺寸的增加，其挑战性越来越大。然后，标准的准备技术需要大量的操作或缓慢的绝热演化，并且仅允许访问有限的一组状态。在这里，我们使用量子最优控制理论来克服此问题，并导出成形的射频脉冲以实验性地导航Rydberg原子的Stark流形。我们证明，除了提高现有协议的保真度之外，最佳控制还使我们能够准确生成无法使用标准技术以合理保真度准备的非经典叠加状态。因此，最佳控制会大大扩大可访问状态的范围。