近日，澳大利亚墨尔本皇家理工大学Jean-Philippe Tetienne团队研究了光学可寻址固态自旋对的电荷转移机制。相关论文发表在2025年11月19日出版的《自然—物理学》杂志上。
六方氮化硼中的明亮点缺陷发射器在量子传感等领域具有应用潜力。然而，观测到的缺陷微观结构难以准确识别，这制约了相关技术的进一步发展。人们发现，在宽波长范围内出现的某类明亮发射器虽能呈现光学探测磁共振现象，却无分辨清晰的零场分裂信号。尽管此类现象被多次观测，其缺陷微观结构及光学探测磁共振的物理起源仍不明确。
研究组通过构建受自旋化学中自由基对机制启发的理论模型，首次为群体与单发射器的自旋分辨光动力学所有关键实验特征提供了物理解释。该模型假设存在两个相邻的点缺陷，其中仅一个具有光学活性。基于第一性原理计算，研究组证实由常见碳缺陷构成的简单缺陷对可实现该理论模型。该研究不仅解决了六方氮化硼缺陷领域的若干核心问题，也可能适用于其他宽带隙半导体中观测到的类似现象。
附：英文原文
Title: A charge transfer mechanism for optically addressable solid-state spin pairs
Author: Robertson, Islay O., Whitefield, Benjamin, Scholten, Sam C., Singh, Priya, Healey, Alexander J., Reineck, Philipp, Kianinia, Mehran, Barcza, Gergely, Ivdy, Viktor, Broadway, David A., Aharonovich, Igor, Tetienne, Jean-Philippe
Issue&Volume: 2025-11-19
Abstract: Bright point-defect emitters in hexagonal boron nitride have potential applications in quantum sensing and other technologies. However, it can be difficult to correctly identify the microscopic nature of observed defects, creating challenges for further development. A class of bright emitters exhibiting optically detected magnetic resonance with no resolvable zero-field splitting has been observed in hexagonal boron nitride across a broad range of wavelengths. However, the microscopic structure of the defects and the physical origin of their optically detected magnetic resonance signal have still not been identified. Here we describe a model that accounts for and provides a physical explanation for all key experimental features of the spin-resolved photodynamics of ensembles and single emitters. The model, inspired by the radical-pair mechanism from spin chemistry, assumes a pair of nearby point defects, one of which is optically active. Using first-principles calculations, we show that simple defect pairs made of common carbon defects provide a plausible realization of our model. As well as addressing open questions about defects in hexagonal boron nitride, our model may also explain similar phenomena observed in other wide-bandgap semiconductors.
DOI: 10.1038/s41567-025-03091-5
Source: https://www.nature.com/articles/s41567-025-03091-5