First principles calculation of spin-related quantities for point defect qubit research （点缺陷量子比特研究中自旋相关量的第一性原理计算）
Viktor Ivády,Igor A. Abrikosov & Adam Gali 
npj Computational Materials 4:76 (2018)
doi:s41524-018-0132-5
Published online:12 December 2018
Abstract| Full Text | PDF OPEN

摘要:由于能够识别具有独特特性的量子比特和单光子发射器的特殊点缺陷，半导体点缺陷研究获得了巨大的新动力。实际上，这些工作是量子技术中少数几种替代方案，甚至可以在室温下运行，因此新点缺陷的发现和表征，可以极大地促进未来的固态量子技术。第一原理计算在点缺陷研究中起着重要作用，因为其可以直接、深入地了解缺陷态的形成。在过去的几十年中，为了能用第一原理计算来研究点缺陷的自旋相关特性，人们已经做出了相当大的努力。所开发出的方法已经证明其在定量理解点缺陷量子比特的物理和应用方面具有重要作用。本文综述和讨论了这些新从头方法的准确性，提出它们与半导体中现有点缺陷量子比特紧密相关的应用。我们关注了解决方法方案的优势和局限性，重点指出了不久可能出现的进展。此外，我们讨论了对潜在点缺陷量子比特进行系统搜索的可能性，以及从头算方法计算自旋相关量对预测自旋动力学模拟的促进作用。 　　

Abstract:Point defect research in semiconductors has gained remarkable new momentum due to the identification of special point defects that can implement qubits and single photon emitters with unique characteristics. Indeed, these implementations are among the few alternatives for quantum technologies that may operate even at room temperature, and therefore discoveries and characterization of novel point defects may highly facilitate future solid state quantum technologies. First principles calculations play an important role in point defect research, since they provide a direct, extended insight into the formation of the defect states. In the last decades, considerable efforts have been made to calculate spin-dependent properties of point defects from first principles. The developed methods have already demonstrated their essential role in quantitative understanding of the physics and application of point defect qubits. Here, we review and discuss accuracy aspects of these novel ab initio methods and report on their most relevant applications for existing point defect qubits in semiconductors. We pay attention to the advantages and limitations of the methodological solutions and highlight additional developments that are expected in the near future. Moreover, we discuss the opportunity of a systematic search for potential point defect qubits, as well as the possible development of predictive spin dynamic simulations facilitated by ab initio calculations of spin-dependent quantities.