AI 中文总结
该研究开发了结合第一性原理计算与实验验证的框架，揭示金刚石缺陷环境对量子退相干的影响，为优化缺陷基量子材料的退相干提供预测方法。
AI 中文摘要
由缺陷诱导的量子退相干仍是固态量子技术的主要限制因素，但预测真实材料中的退相干在计算上仍具挑战性。复杂的缺陷群常被近似为均匀自旋浴，掩盖了缺陷特定电子结构与自旋动力学的作用。本文通过结合第一性原理电子结构计算、量子多体自旋浴模拟与实验验证，开发了金刚石中退相干的预测框架。该框架纳入了缺陷分辨的自旋哈密顿量与含多种顺磁缺陷种类的非均匀自旋浴。以金刚石氮-空位系综为模型平台，研究了混合氮、空位与氢相关的缺陷环境。结果表明，退相干不仅依赖于缺陷密度，还取决于缺陷种类与浴组分，其独特的电子结构、超精细相互作用与自旋动力学产生不同的相干行为。非均匀缺陷群可抑制或增强退相干，产生均匀浴模型无法解释的趋势。对不同缺陷浓度样品的磁场依赖Hahn回波测量验证了该框架，计算在宽磁场范围内复现了观测到的相干时间与 stretched-exponential 衰减行为，并确定空位相关缺陷是超出传统假设的P1自旋浴之外的关键贡献者。通过将原子级缺陷性质与量子相干性关联，该框架为识别隐藏缺陷环境及优化基于缺陷的量子材料中的退相干提供了预测途径。
英文摘要
Quantum decoherence induced by defects remains a major limitation for solid-state quantum technologies, yet predicting decoherence in realistic materials remains computationally challenging. Complex defect populations are often approximated as homogeneous spin baths, obscuring the role of defect-specific electronic structure and spin dynamics. Here, we develop a predictive framework for decoherence in diamond by combining first-principles electronic-structure calculations, quantum many-body spin-bath simulations, and experimental validation. The framework incorporates defect-resolved spin Hamiltonians and heterogeneous spin baths containing multiple paramagnetic defect species. Using diamond nitrogen-vacancy ensembles as a model platform, we investigate mixed nitrogen-, vacancy-, and hydrogen-related defect environments. We show that decoherence depends not only on defect density but also on defect identity and bath composition, whose distinct electronic structures, hyperfine interactions, and spin dynamics produce different coherence behavior. Heterogeneous defect populations can either suppress or enhance decoherence, producing trends unexplained by homogeneous-bath models. Magnetic-field-dependent Hahn-echo measurements on samples with different defect concentrations validate the framework. The calculations reproduce the observed coherence times and stretched-exponential decay behavior across a broad magnetic-field range and identify vacancy-related defects as critical contributors beyond the conventionally assumed P1 spin bath. By linking atomistic defect properties to quantum coherence, our framework provides a predictive route for identifying hidden defect environments and optimizing decoherence in defect-based quantum materials.
Comments34 pages, 5 figures, 2 tables
