Multiconfigurational study of the negatively charged nitrogen-vacancy center in diamond
Multiconfigurational study of the negatively charged nitrogen-vacancy center in diamond
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DOI：
10.1103/physrevb.103.014115
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发表时间：
2021-01-25
影响因子：
3.7
通讯作者：
Park, Kyungwha
中科院分区：
文献类型：
--
作者：
Bhandari, Churna;Wysocki, Aleksander L.;Park, Kyungwha
宽禁带半导体中的深度缺陷已成为实现量子传感和信息应用的主要量子比特候选者。由于缺陷状态的空间局部性，这些深度缺陷可以被认为是固态矩阵中的人造原子/分子。本文表明，与单粒子处理不同，传统上用于原子/分子的多构型量子化学方法准确地描述了这些缺陷中心的电子态的多体特征，并正确地预测了单粒子处理无法获得的性质。我们选择金刚石中带负电荷的氮空位（NV-）中心作为原型缺陷进行这些技术的研究，是因为它对量子信息应用的重要性以及它的性质是众所周知的，这使它成为一个理想的基准体系。通过在量子化学计算中适当地考虑电子相关性并包括自旋-轨道耦合和偶极自旋-自旋耦合，对于金刚石团簇中的NV-中心，我们能够：(i)证明了基态（第一激发态）自旋三重态分裂为两个能级（四个能级），（ii）计算了基态和激发态自旋三重态的零场分裂值，与实验结果一致，（iii）确定了自旋单重态的多体构型，（iv）计算了基态和激发态自旋三重态和自旋单重态之间的能量差及其排序。这也与最近的实验数据吻合得很好。我们所开发的数值计算程序具有通用性，并且可以筛选其他性质尚不清楚但有应用前景的色心。
Deep defects in wide band gap semiconductors have emerged as leading qubit candidates for realizing quantum sensing and information applications. Due to the spatial localization of the defect states, these deep defects can be considered as artificial atoms/molecules in a solid state matrix. Here we show that unlike single-particle treatments, the multiconfigurational quantum chemistry methods, traditionally reserved for atoms/molecules, accurately describe the many-body characteristics of the electronic states of these defect centers and correctly predict properties that single-particle treatments fail to obtain. We choose the negatively charged nitrogen-vacancy (NV-) center in diamond as the prototype defect to study with these techniques due to its importance for quantum information applications and because its properties are well known, which makes it an ideal benchmark system. By properly accounting for electron correlations and including spin-orbit coupling and dipolar spin-spin coupling in the quantum chemistry calculations, for the NV- center in diamond clusters, we are able to: (i) show the correct splitting of the ground (first-excited) spin-triplet state into two levels (four levels), (ii) calculate zero-field splitting values of the ground and excited spin-triplet states, in good agreement with experiment, (iii) determine many-body configurations of the spin-singlet states, and (iv) calculate the energy differences between the ground and exited spin-triplet and spin-singlet states, as well as their ordering, which are also found to be in good agreement with recent experimental data. The numerical procedure we have developed is general, and it can screen other color centers whose properties are not well known but promising for applications.