Noise-induced collective quantum state preservation in spin qubit arrays
Noise-induced collective quantum state preservation in spin qubit arrays
复制标题
自旋量子位阵列中噪声引起的集体量子态保存
DOI：
10.1103/physrevb.93.085420
复制
发表时间：
2015
影响因子：
3.7
通讯作者：
S. Sarma
中科院分区：
文献类型：
--
作者：
Edwin Barnes;D. Deng;R. Throckmorton;Yang;S. Sarma
与核自旋（或Overhauser噪声）的超精细相互作用长期以来一直被视为单个量子点自旋量子比特中退相干的主要来源。在这里，我们表明，在一个耦合的多量子比特系统组成的少至四个自旋，与核自旋的相互作用可以有相反的效果，而不是保持系统的集体量子态。这种噪声诱导的状态保持可以使用当前的技术能力在线性自旋量子位阵列中实现。我们的建议不需要控制阵列中的Overhauser场;只需要对最近邻居之间的平均量子位间耦合进行实验控制，这很容易通过调整栅极电压来实现。我们的研究结果说明了环境的作用如何从有害转变为有益，从单量子比特到多量子比特的量子系统。
The hyperfine interaction with nuclear spins (or, Overhauser noise) has long been viewed as a leading source of decoherence in individual quantum dot spin qubits. Here we show that in a coupled multi-qubit system consisting of as few as four spins, interactions with nuclear spins can have the opposite effect where they instead preserve the collective quantum state of the system. This noise-induced state preservation can be realized in a linear spin qubit array using current technological capabilities. Our proposal requires no control over the Overhauser fields in the array; only experimental control over the average interqubit coupling between nearest neighbors is needed, and this is readily achieved by tuning gate voltages. Our results illustrate how the role of the environment can transform from harmful to helpful in the progression from single-qubit to multi-qubit quantum systems.