Controllable, partially isolated few level systems in semiconductors have recently gained multidisciplinary attention due to their widespread nanoscale sensing and quantum technology applications. Quantitative simulation of the dynamics and related applications of such systems is a challenging theoretical task that requires faithful description not only the few level systems but also their local environments. Here, we develop a method that can describe relevant relaxation processes induced by a dilute bath of nuclear and electron spins. The method utilizes an extended Lindblad equation in the framework of cluster approximation of a central spin system. We demonstrate that the proposed method can accurately describe T$_1$ time of an exemplary solid-state point defect qubit system, in particular NV center in diamond, at various magnetic fields and strain.
Nuclear spin relaxation in solid state defect quantum bits via electron-phonon coupling in their optical excited state
HUN-REN Wigner Research Centre for Physics（匈牙利科学院维格纳物理研究中心）；Budapest University of Technology and Economics（布达佩斯科技大学）；MTA-WFK Lendület “Momentum” Semiconductor Nanostructures Research Group（匈牙利科学院-布达佩斯技术大学伦戴莱特“动量”半导体纳米结构研究组）
A defect in diamond with millisecond-scale spin relaxation time at room temperature
Princeton University（普林斯顿大学）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；US Naval Research Laboratory（美国海军研究实验室）；University of North Carolina at Chapel Hill（北卡罗来纳大学教堂山分校）；University of Iowa（爱荷华大学）
Spin-Phonon Relaxation of Boron-Vacancy Centers in Two-Dimensional Boron Nitride Polytypes
Isfahan University of Technology（伊斯法罕理工大学）；HUN-REN Wigner Research Centre for Physics（匈牙利研究与教育网络维格纳物理研究中心）；Budapest University of Technology and Economics（布达佩斯技术与经济大学）
