AI 中文总结
本文针对金刚石IV族空位色心的自旋退相干问题，采用非马尔可夫方法修正马尔可夫近似的偏差，阐明磁场取向对量子比特相干时间的影响，实现对实验结果的一致复现。
AI 中文摘要
量子比特相干性是量子计算、量子中继器等量子信息处理应用的关键性能指标。支撑这些应用的物理量子比特的相干性特性常受晶格声子耦合限制，进而约束了工作温度。本文研究金刚石中IV族空位色心内声子诱导的电子自旋退相干，先对自旋-声子相互作用建模，再采用广泛使用的玻恩-马尔可夫近似，指出其在该场景下的不一致性及与实验观测的偏差。为弥合理论预测与实验结果的差距，本文放宽部分近似，研究其对预测相干时间的贡献，明确偏差的主导来源；进一步证明，非马尔可夫框架可一致地复现实验测得的电子自旋相干动力学，还阐明了磁场取向对量子比特相干时间的影响。
英文摘要
Qubit coherence is an essential figure of merit for quantum information processing applications such as quantum computing, or quantum repeaters. Understanding the coherence properties of the underlying physical qubits that facilitate such applications is therefore are often limited by coupling to lattice phonons, which in turn constrains operation temperature. Here we study phonon induced electronic spin decoherence in group-IV vacancy centers in diamond. We begin by modeling the spin-phonon interaction and then employ the widely used Born-Markov approximation, highlighting its inconsistencies in this setting and its deviations from experimental observations. To close the gap between theoretical predictions and experimental results, we relax certain approximations, investigate their contributions to the predicted coherence times, and identify the dominant sources of discrepancy. We further demonstrate that experimentally measured electronic spin coherence dynamics are consistently captured within a non-Markovian framework, and we show how the magnetic field orientation influences the qubit coherence time.
Comments12 pages, 7 figures
