Stability and molecular pathways to the formation of spin defects in silicon carbide.
Stability and molecular pathways to the formation of spin defects in silicon carbide.
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DOI：
10.1038/s41467-021-26419-0
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发表时间：
2021-11-03
影响因子：
16.6
通讯作者：
Galli G
中科院分区：
文献类型：
--
作者：
Lee EMY;Yu A;de Pablo JJ;Galli G
宽带隙半导体中的自旋缺陷为创建量子技术的量子位提供了一个有前途的平台。然而，它们的合成提出了相当大的挑战，并且对其产生或消灭的机制知之甚少。在这里，我们阐明了二元晶体中关键量子位候选物——碳化硅（SiC）中的双空位复合物（VV）的自旋缺陷形成过程。利用原子模型、增强采样模拟和密度泛函理论计算，我们发现VV形成是一个热激活过程，与硅（VSi）向碳单空位（VC）的转化竞争，并且VV重新取向可以在不解离的情况下发生。我们还发现，增加 VSi 相对于 VC 的浓度有利于双空位的形成。此外，我们还确定了产生由反位点双空位复合物组成的自旋缺陷的途径，并确定了它们的电子特性。这里提出的支持自旋缺陷形成和动力学的机制的详细视图可能有助于在工业相关材料中实现量子位。了解固态自旋缺陷的形成机制为其未来在量子技术中的应用奠定了基础。在这里，作者结合从头算分子动力学、增强采样和密度泛函理论来阐明碳化硅中自旋缺陷的形成过程。
Spin defects in wide-bandgap semiconductors provide a promising platform to create qubits for quantum technologies. Their synthesis, however, presents considerable challenges, and the mechanisms responsible for their generation or annihilation are poorly understood. Here, we elucidate spin defect formation processes in a binary crystal for a key qubit candidate—the divacancy complex (VV) in silicon carbide (SiC). Using atomistic models, enhanced sampling simulations, and density functional theory calculations, we find that VV formation is a thermally activated process that competes with the conversion of silicon (VSi) to carbon monovacancies (VC), and that VV reorientation can occur without dissociation. We also find that increasing the concentration of VSi relative to VC favors the formation of divacancies. Moreover, we identify pathways to create spin defects consisting of antisite-double vacancy complexes and determine their electronic properties. The detailed view of the mechanisms that underpin the formation and dynamics of spin defects presented here may facilitate the realization of qubits in an industrially relevant material. Understanding the mechanism of formation of solid-state spin defects underpins their future applications in quantum technologies. Here, the authors use a combination of ab initio molecular dynamics, enhanced sampling, and density functional theory to clarify the formation process of spin defects in silicon carbide.
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影响因子：
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