基于碳化硅晶体色心的自旋单量子态构筑和测量的理论模拟

项目名称： 基于碳化硅晶体色心的自旋单量子态构筑和测量的理论模拟

项目编号： No.91221101

项目类型： 重大研究计划

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 赵明文

作者单位： 山东大学

项目金额： 70万元

中文摘要： 金刚石是量子信息领域的基础材料之一。利用其中的NV中心可以实现自旋单量子态的构筑、操作和测量。但是目前金刚石在材料生长和器件加工方面进展缓慢。碳化硅晶体具有与金刚石相似的原子结构，且生长和加工工艺相对成熟。本项目拟由碳化硅晶体中与空位相关的色心的基态电子结构和激发态特性的理论模拟出发，探索在碳化硅晶体中实现自旋单量子态的构筑、操作和测量的可能性，为最终利用“廉价”的碳化硅取代“昂贵”的金刚石提供理论基础。本项目将采用密度泛函理论和从Bethe-Salpeter方程出发的多体微扰理论研究碳化硅中(1) 色心的结构对称性、色心周围原子的电负性、以及色心的电荷态对其基态和激发态电子结构的调控规律；(2) 色心激发态结构演化的势能面以及激发态到基态跃迁通道中的中间态。在此基础上确定出适合自旋单量子态构筑和测量的色心结构，并为实验提供“激发能量”和“光谱特性”等关键的物理参量，推动实验研究的进展。

中文关键词： 固体量子比特；碳化硅；缺陷中心；电子自旋；量子力学第一性原理

英文摘要： Diamond is quite promising for the application in the field of quantum information, because the so-called NV centers composing of a substitutional nitrogen atom and an adjacent vacancy defect in diamond are available for achieving the construction, manipulation, and measurement of single spin quantum state (SSQS). However, their manufacture is still embryonic and expensive, so the potential for expanding to large-scale quantum processor using diamond remain uncertain. Silicon carbide crystals possess similar tetrahedral atomic arrangement as that in diamond, but its manufacture has been well-established. In this project, we will investigate the plausibility of using the color centers in silicon carbide to achieve the construction, manipulation, and measurement of SSQS, aiming at the replacement of ‘expensive’ diamond by ‘cheaper” silicon carbide crystals in the field of quantum information. Density-functional theory and many-body perturbation theory on the basis of Bethe-Salpeter equation will be employed in the study of the following issues. (1) The roles of structural symmetry, the electronegativities of the atoms nearest to the vacancy defect, and the charge states of the color centers in silicon carbide crystals in tuning their electronic structures of ground states and excite states; (2) The potential energ

英文关键词： solid state quantum spin bits；silicon carbide；defect center；electron spin；first-principles calculations