Experimental realization of universal geometric quantum gates with solid-state spins

摘要

开发实用量子计算机所面临的一个障碍是，人们认为需要实质性的纠错方案。然而这种方案会降低计算速度，削弱量子枝术的一些潜在优势。另一种办法是利用具有固有容错能力的量子计算原理，它们抗噪音（如由于几何规则的保护所产生的噪音）能力强。目前已经报告了一些全几何量子计算实验，但所面临的挑战是找到一个可升级的平台。现在，Luming Duan及同事报告了具有普遍性的一组几何量子门(其中自旋位于金刚石缺陷中心内）的实验实现。虽然这些实验是基于一个金刚石中心内的两个量子位，但这项工作为在固体状态和室温下工作的全几何、抗噪音量子计算提供了一个有希望的方向。%Experimental realization of a universal set of quantum logic gates is the central requirement for the implementation of a quantum computer. In an 'all-geometric' approach to quantum computation the quantum gates are implemented using Berry phases and their non-Abelian extensions, holonomies, from geometric transformation of quantum states in the Hilbert space. Apart from its fundamental interest and rich mathematical structure, the geometric approach has some built-in noise-resilience features. On the experimental side, geometric phases and holonomies have been observed in thermal ensembles of liquid molecules using nuclear magnetic resonance; however, such systems are known to be non-scalable for the purposes of quantum computing. There are proposals to implement geometric quantum computation in scalable experimental platforms such as trapped ions superconducting quantum bits and quantum dots, and a recent experiment has realized geometric single-bit gates in a superconducting system. Here we report the experimental realization of a universal set of geometric quantum gates using the solid-state spins of diamond nitrogen-vacancy centres. These diamond defects provide a scalable experimental platform with the potential for room-temperature quantum computing, Which has attracted strong interest in recent years. Our experiment shows that all-geometric and potentially robust quantum computation can be realized with solid-state spin quantum bits, making use of recent advances in the coherent control of this system.