金刚石纳米颗粒中氮空位色心的电子自旋研究

通过电子注入的方法制备了含氮空位色心单光子源的金刚石荧光纳米颗粒. 自旋回声测试结果表明, 纳米颗粒中氮空位色心的相干时间T₂很短, 介于0.86 μs至5.6 μs之间. Ramsey干涉条纹测试结果表明, 氮空位色心NV1点的退相干时间T₂^* 最大, 为0.7 μs, 其电子自旋共振谱可分辨的最小线宽为1.05 MHz. 并且NV1点的电子自旋共振谱可分辨氮空位色心本身的¹⁴N核自旋与 氮空位色心电子自旋之间的2.2 MHz超精细相互作用, 这对于在金刚石纳米颗粒中实现核自旋的操控和多个量子比特的门操作具有重要意义. 关键词： 纳米颗粒 氮空位色心 电子自旋

Electron spin studies of nitrogen vacancy centers in nanodiamonds*

Fluorescent nanodiamonds containing nitrogen vacancy centers are created by electron irradiation. The values of spin echo coherence time T₂ of nitrogen vacancy centers in nanodiamonds are very small, which are between 0.86 μs and 5.6 μs. The results of Ramsey interference fringes show that the values of dephasing time T₂^* differ from each other and the T₂^* of nitrogen vacancy center NV1 is biggest (0.7 μs). Its inhomogeneous linewidth obtained from Fourier transform frequency spectrum of Ramsey interference fringes is 1.05 MHz. The hyperfine structure for the nitrogen vacancy center electron spin coupled to the host nitrogen-14 nuclear spin can be detected by the electron spin resonance spectrum in nitrogen vacancy center NV1. It is important for the realization of the manipulation of nuclear spins and quantum gates of multiqubit in nanodiamonds.
Keywords： nanodiamond nitrogen vacancy center electron spin