AI 中文总结
该研究通过第一性原理计算发现，六方金刚石蓝丝黛尔石的AB构型氮空位中心，在零磁场下的Hahn回波相干时间T₂较立方金刚石同类中心提升约4倍，有望用于量子传感与信息科学领域。
AI 中文摘要
我们表明，六方金刚石多型蓝丝黛尔石（lonsdaleite）中带负电的氮空位（NV）中心，相比立方金刚石中的同类中心，为自旋量子比特提供了相干性增强的途径。我们采用第一性原理计算，研究了两种不同的缺陷构型：与立方金刚石对称性相同的AA构型，以及对称性降低的AB构型。我们发现，NV中心的AB构型呈现出有限的横向零场分裂，这导致在零磁场下， Hahn回波相干时间T₂近似提升了4倍。相比之下，AA构型紧密重现了立方NV中心的电子结构和相干特性。我们进一步表征了两种构型的多体电子结构、垂直激发能和光致发光光谱，为实验识别它们提供了光谱指纹。我们的结果确立了蓝丝黛尔石中对称性破缺的NV中心，是量子传感和信息科学应用的有前途候选者。
英文摘要
We show that negatively charged nitrogen-vacancy (NV) centers in the hexagonal diamond polymorph lonsdaleite offer a route to spin qubits with enhanced coherence relative to their cubic-diamond counterparts. Using first-principles calculations, we examine two distinct defect configurations, AA, with the same symmetry as in cubic diamond and AB, with reduced symmetry. We find that the AB configuration of the NV center exhibits a finite transverse zero-field splitting, giving rise to an approximate fourfold enhancement of the Hahn-echo coherence time $T_2$ at zero magnetic field. The AA configuration, by contrast, closely reproduces the electronic structure and coherence properties of the cubic NV center. We further characterize the many-body electronic structure, vertical excitation energies, and photoluminescence spectra of both configurations, providing spectral fingerprints for their experimental identification. Our results establish symmetry-broken NV centers in lonsdaleite as promising candidates for quantum sensing and information science applications.
Comments6 pages, 4 figures, data and codes uploaded on QRESP after final peer review complete
