Optimal photon energies for initialization of hybrid spin quantum registers of nitrogen-vacancy centers in diamond
Optimal photon energies for initialization of hybrid spin quantum registers of nitrogen-vacancy centers in diamond
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DOI：
10.1103/physreva.101.013835
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发表时间：
2019-02
影响因子：
2.9
通讯作者：
K. R. K. Rao-K.-R.-K.-Rao-2107738450;Yihua H. Wang;Zi-Yue Zhang;D. Suter
中科院分区：
文献类型：
--
作者：
K. R. K. Rao-K.-R.-K.-Rao-2107738450;Yihua H. Wang;Zi-Yue Zhang;D. Suter
高保真度初始化量子寄存器是量子信息处理和传感等许多应用的基本前提。金刚石中氮空位（NV）中心的电子和核自旋形成了一个有趣的混合量子寄存器，可以通过激光、微波和射频脉冲的组合来初始化。然而，实现电子自旋极化所必需的激光照射也具有使核自旋去极化的副作用。在这里，我们研究 $^{14}\mathrm{N}$ 核自旋的去极化动力学如何取决于激光波长。我们通过实验证明，与通常用于激发的绿色激光（532 nm）相比，橙色激光（594 nm）的激发引起的核自旋去极化明显减少，因此导致更高的核自旋极化。这可能是因为橙色光激发抑制 ${\mathrm{NV}}^{0}$ 电离为 ${\mathrm{NV}}^{\ensuremath{-}}$ ，因此抑制了作用于核自旋的噪声源之一。
Initializing quantum registers with high fidelity is a fundamental precondition for many applications like quantum information processing and sensing. The electronic and nuclear spins of a nitrogen-vacancy (NV) center in diamond form an interesting hybrid quantum register that can be initialized by a combination of laser, microwave, and radio-frequency pulses. However, the laser illumination, which is necessary for achieving electron spin polarization, also has the unwanted side effect of depolarizing the nuclear spin. Here we study how the depolarization dynamics of the $^{14}\mathrm{N}$ nuclear spin depends on the laser wavelength. We show experimentally that excitation with an orange laser (594 nm) causes significantly less nuclear spin depolarization compared to the green laser (532 nm) typically used for excitation and hence leads to higher nuclear spin polarization. This could be because orange light excitation inhibits ionization of ${\mathrm{NV}}^{0}$ into ${\mathrm{NV}}^{\ensuremath{-}}$ and therefore suppresses one source of noise acting on the nuclear spin.