标题： 缺陷诱导的二维碳化硅量子特性：从局域和杂化DFT计算中的原子级洞察 显示英文标题

标题： Vacancy-Induced Quantum Properties in 2D Silicon Carbide: Atomistic insights from semi-local and hybrid DFT calculations

摘要： 二维（2D）材料已成为量子技术和光电子学的有前景的平台，缺陷在其特性中起着关键作用。 我们对单层碳化硅（1L-SiC）中的硅和碳空位进行了全面的第一性原理研究，这是一种具有室温量子应用潜力的宽禁带二维半导体。 使用PBE、SCAN、r$^2$SCAN和HSE06泛函，我们揭示了硅空位和碳空位之间的显著特征差异。 形成能和电荷转变能级表现出强烈的泛函依赖性，与PBE计算相比，HSE06始终预测更高的值和更深的转变能级。 电子结构分析表明了相反的行为：硅空位产生高度局域化的状态并具有强自旋极化，而碳空位则产生更分散的状态且磁性较弱。 空位迁移研究显示，硅空位的迁移能垒明显低于碳空位，表明在中等温度下硅空位具有更高的迁移性。 使用PBE-DFPT计算的光学性质显示，在远红外区域存在与电荷状态相关的吸收，两种空位的正电荷状态表现出最强的响应。 硅空位和碳空位的互补特性——局域化与分散态、不同的磁性特性和不同的光学响应——表明在量子和光电子应用中缺陷工程的可能性。 我们的结果突显了先进泛函在准确描述缺陷特性中的关键重要性，并为理解二维材料中空位行为提供了全面的框架。 显示英文摘要

摘要： Two-dimensional (2D) materials have emerged as promising platforms for quantum technologies and optoelectronics, with defects playing a crucial role in their properties. We present a comprehensive density functional theory study of silicon and carbon vacancies in monolayer silicon carbide (1L-SiC), a wide-bandgap 2D semiconductor with potential for room-temperature quantum applications. Using PBE, SCAN, r$^2$SCAN, and HSE06 functionals, we reveal distinct characteristics between Si and C vacancies. Formation energies and charge transition levels show strong functional dependence, with HSE06 consistently predicting higher values and deeper transition levels compared to PBE calculations. Electronic structure analysis demonstrates contrasting behavior: silicon vacancies create highly localized states with strong spin polarization, while carbon vacancies produce more dispersed states with weaker magnetic properties. Vacancy migration studies reveal significantly lower barriers for silicon vacancies compared to carbon vacancies, indicating higher mobility for Si vacancies at moderate temperatures. Optical properties, calculated using PBE-DFPT, show distinct charge-state dependent absorption in the far-infrared region, with positively charged states of both vacancy types demonstrating the strongest response. The complementary characteristics of Si and C vacancies - localized versus dispersed states, different magnetic properties, and distinct optical responses - suggest possibilities for defect engineering in quantum and optoelectronic applications. Our results highlight the critical importance of advanced functionals in accurately describing defect properties and provide a comprehensive framework for understanding vacancy behavior in 2D materials.