论文标题
在原子的遥远状态之间证明量子腕骨
Demonstration of quantum brachistochrones between distant states of an atom
论文作者
论文摘要
通过最快的途径将初始量子状态转变为目标状态---量子腕骨---对于基于量子力学的许多技术而言，这是一个基本挑战。在这里，我们在其大小的15倍的距离内证明了将原子波包的快速运输---量子过程的范式情况，在该量子过程中，无法通过局部变换达到目标状态。我们对运输保真度的测量表明，对于物质波的相干分裂和重组，量子速度限制的最小持续时间存在。我们通过依靠量子状态动力学的几何解释来获得对这一限制的物理见解。这些结果阐明了量子状态动力学的基本限制，并有望在量子传感和量子计算中找到相关的应用。
Transforming an initial quantum state into a target state through the fastest possible route---a quantum brachistochrone---is a fundamental challenge for many technologies based on quantum mechanics. Here, we demonstrate fast coherent transport of an atomic wave packet over a distance of 15 times its size---a paradigmatic case of quantum processes where the target state cannot be reached through a local transformation. Our measurements of the transport fidelity reveal the existence of a minimum duration---a quantum speed limit---for the coherent splitting and recombination of matter waves. We obtain physical insight into this limit by relying on a geometric interpretation of quantum state dynamics. These results shed light upon a fundamental limit of quantum state dynamics and are expected to find relevant applications in quantum sensing and quantum computing.
