论文标题
同位素纯化诱导的旋转松弛和旋转相干时间在半导体中的减少
Isotope purification induced reduction of spin relaxation and spin coherence times in semiconductors
论文作者
论文摘要
顺磁性缺陷和核自旋通常是通过半导体中光学上可寻址点缺陷旋转实现的固态量子量的重谐和自旋松弛的主要来源。人们普遍认为，核自旋的高度消耗可以通过减少磁噪声来增强连贯性时间。在这里，我们表明，当电子和核自旋都存在于Qubits附近时，同位素纯化超出了一定最佳水平。使用最先进的数值工具并考虑各种自旋环境中的硅空位二极管，我们证明了与晶格中的Spin-1/2点缺陷的耦合可以通过同位素纯化可显着增强。增强的耦合缩短了自旋松弛时间，而自旋松弛时间又可能会限制自旋量子的相干时间。我们的结果可以直接概括为三重姿势缺陷量矩，例如Diamond的NV中心和SIC的DivaCagicance。
Paramagnetic defects and nuclear spins are often the major sources of decoherence and spin relaxation in solid-state qubits realized by optically addressable point defect spins in semiconductors. It is commonly accepted that a high degree of depletion of nuclear spins can enhance the coherence time by reducing magnetic noise. Here we show that the isotope purification beyond a certain optimal level becomes contra-productive, when both electron and nuclear spins are present in the vicinity of the qubits. Using state-of-the-art numerical tools and considering the silicon vacancy qubit in various spin environments, we demonstrate that the coupling to spin-1/2 point defects in the lattice can be significantly enhanced by isotope purification. The enhanced coupling shortens the spin relaxation time that in turn may limit the the coherence time of spin qubits. Our results can be straightforwardly generalized to triplet point defect qubits, such as the NV center in diamond and the divacancy in SiC.
