Department of Physics and Center for Quantum Coherence, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
Phys Rev Lett. 2011 May 27;106(21):217205. doi: 10.1103/PhysRevLett.106.217205. Epub 2011 May 26.
Decoherence of quantum objects in noisy environments is important in quantum sciences and technologies. It is generally believed that different processes coupled to the same noise source have similar decoherence behaviors and stronger noises cause faster decoherence. Here we show that in a quantum bath, the case can be the opposite. We predict that the multitransition of a nitrogen-vacancy center spin-1 in diamond can have longer coherence time than the single transitions, even though the former suffers twice stronger noises from the nuclear spin bath than the latter. This anomalous decoherence effect is due to manipulation of the bath evolution via flips of the center spin.
在量子科学和技术中，量子物体在嘈杂环境中的退相干是很重要的。人们普遍认为，与同一噪声源耦合的不同过程具有相似的退相干行为，而较强的噪声会导致更快的退相干。在这里，我们表明在量子浴中情况可能正好相反。我们预测，即使氮空位中心自旋-1在金刚石中的多跃迁比单跃迁受到来自核自旋浴强两倍的噪声，前者也可以具有更长的相干时间。这种反常的退相干效应是由于通过中心自旋的翻转来操纵浴演化。
