Quantum optimal control theory is becoming increasingly crucial as quantum devices become more precise, but the need to quickly optimize these systems classically remains a significant bottleneck in their operation. Here we present a new theoretical quantum control framework for much faster optimization than the state of the art by replacing standard time propagation with a product of short-time propagators, each calculated using the Magnus expansion. The derived formulas for exact series terms and their gradients, based on earlier approximate integrals in a simulation setting, allow us to subsume the high cost of calculating commutators and integrals as an initial overhead. This provides an order of magnitude speedup for quantum control optimization.

中文翻译：

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量子最优控制理论中的快速、高精度动力学

随着量子设备变得越来越精确，量子最优控制理论变得越来越重要，但快速优化这些系统的经典需求仍然是其运行中的一个重大瓶颈。在这里，我们提出了一种新的理论量子控制框架，通过将标准时间传播替换为短时传播子的乘积来实现比现有技术更快的优化，每个短时传播子都使用 Magnus 展开计算。基于模拟设置中较早的近似积分，精确级数项及其梯度的派生公式使我们能够将计算换向器和积分的高成本作为初始开销。这为量子控制优化提供了一个数量级的加速。