Effect of lattice relaxation on spin density of nitrogen-vacancy centers in diamond and oscillator strength calculations
Effect of lattice relaxation on spin density of nitrogen-vacancy centers in diamond and oscillator strength calculations
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DOI：
10.1140/epjb/e2011-20370-0
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发表时间：
2011-11
期刊：
影响因子：
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通讯作者：
M. Babamoradi;M. Heidari Saani;A. Ranjbar;M. Vesaghi;Y. Kawazoe
中科院分区：
文献类型：
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作者：
M. Babamoradi;M. Heidari Saani;A. Ranjbar;M. Vesaghi;Y. Kawazoe
利用广义Hubbard哈密顿量计算了金刚石中负电荷（NV-）和中性氮空位（NV 0）中心的多电子波函数。我们报告的自旋密度上的周围原子的对称弛豫的效果，计算从许多电子波函数在基态和激发态。本文对电子顺磁共振实验中忽略晶格弛豫效应时自旋密度估计的误差进行了评估，并指出在向外弛豫时，基态自旋密度分布是可以得到的。计算的振子强度给出了NV-的1.945 eV光致发光（PL）线相对于NV 0的2.156 eV PL线的更高效率，这与实验吻合得很好。这一结果是基于NV-相对于NV 0的可用值中最大的基态自旋来解释的。简并基态和激发态之间的跃迁几率与Sz值有一定的关系。最后，我们报道了对基态和激发态有贡献的电子组态，并讨论了电子组态随弛豫的布居变化。
Using a generalized Hubbard Hamiltonian, many-electron wavefunctions of negatively charged (NV−) and neutral nitrogen-vacancy (NV0) centers in diamond were calculated. We report the effect of symmetric relaxation of surrounding atoms on the spin density, calculated from the many electron wavefunctions in the ground and excited states. We evaluated the error, that, arises in estimation of spin density when lattice relaxation effect is neglected in Electron Paramagnetic Resonance experiment and showed that the ground state spin density distribution is accessible in outward relaxations. The computed oscillator strengths give a higher efficiency for the 1.945 eV photoluminescence (PL) line of NV−with respect to 2.156 eV PL line of NV0which agrees well with experiment. This result is explained based on the largest the ground state spin among available values for the NV−with respect to NV0. The transition probability between degenerate ground and excited states slightly depends on theSzvalue. Finally, we report on the electronic configurations which contribute to the ground and excited states and discuss the population variation of electronic configurations with relaxation.