Hanson R, Dobrovitski V V, Feiguin A E, Gywat O, Awschalom D D
California Nanosystems Institute, University of California, Santa Barbara, CA 93106, USA.
Science. 2008 Apr 18;320(5874):352-5. doi: 10.1126/science.1155400. Epub 2008 Mar 13.
Phase coherence is a fundamental concept in quantum mechanics. Understanding the loss of coherence is paramount for future quantum information processing. We studied the coherent dynamics of a single central spin (a nitrogen-vacancy center) coupled to a bath of spins (nitrogen impurities) in diamond. Our experiments show that both the internal interactions of the bath and the coupling between the central spin and the bath can be tuned in situ, allowing access to regimes with surprisingly different behavior. The observed dynamics are well explained by analytics and numerical simulations, leading to valuable insight into the loss of coherence in spin systems. These measurements demonstrate that spins in diamond provide an excellent test bed for models and protocols in quantum information.
相位相干是量子力学中的一个基本概念。理解相干性的丧失对于未来的量子信息处理至关重要。我们研究了与金刚石中的自旋（氮杂质）浴耦合的单个中心自旋（氮空位中心）的相干动力学。我们的实验表明，浴的内部相互作用以及中心自旋与浴之间的耦合都可以原位调节，从而能够进入具有惊人不同行为的区域。通过分析和数值模拟可以很好地解释所观察到的动力学，从而对自旋系统中相干性的丧失有了宝贵的见解。这些测量表明，金刚石中的自旋为量子信息中的模型和协议提供了一个极好的测试平台。
