Quantum Walk of a Trapped Ion in Phase Space
Quantum Walk of a Trapped Ion in Phase Space
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DOI：
10.1103/physrevlett.103.090504
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发表时间：
2009-08-28
影响因子：
8.6
通讯作者：
Schaetz, T.
中科院分区：
文献类型：
--
作者：
Schmitz, H.;Matjeschk, R.;Schaetz, T.
我们实现了一个离子在线性离子阱中的量子行走的原理证明。在单步保真度超过0.99的情况下，我们在线上执行三步不对称行走。如果我们允许步行者或离子同时走所有的经典路径，我们清楚地揭示了它与经典对应物的不同之处。量子干涉在高度纠缠的自由度（硬币和位置状态）中实施非对称的非经典分布。我们从理论上研究和实验上观察我们的方法，这是由运动压缩的步骤数的限制。我们提出了一种基于脉冲步骤方法的改进协议来克服这些限制，允许将量子行走扩展到许多步骤，原则上是数百个步骤。
We implement the proof of principle for the quantum walk of one ion in a linear ion trap. With a single-step fidelity exceeding 0.99, we perform three steps of an asymmetric walk on the line. We clearly reveal the differences to its classical counterpart if we allow the walker or ion to take all classical paths simultaneously. Quantum interferences enforce asymmetric, nonclassical distributions in the highly entangled degrees of freedom (of coin and position states). We theoretically study and experimentally observe the limitation in the number of steps of our approach that is imposed by motional squeezing. We propose an altered protocol based on methods of impulsive steps to overcome these restrictions, allowing to scale the quantum walk to many, in principal to several hundreds of steps.