发表机构
Rutgers University; Beijing Academy of Quantum Information Sciences; National Institute of Chemical Physics and Biophysics; University of South Carolina（罗格斯大学; 北京量子信息科学研究院; 化学物理与生物物理学国立研究所; 南卡罗来纳大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过光谱技术在Cr₂O₃中发现三种铬空位诱导的磁性激发，结合第一性原理计算揭示其局域磁激发本质，为量子应用提供潜在缺陷宿主系统。
AI 中文摘要
点缺陷已成功应用于多种量子技术，作为量子计算的量子比特、量子通信的单光子发射器以及量子计量的纳米级传感器。然而，其进一步发展面临关键挑战，尤其是发现和探索满足量子应用必要标准的合适缺陷-宿主系统。本文利用偏振分辨拉曼光谱和太赫兹吸收光谱，在单轴反铁磁绝缘体Cr₂O₃中发现三种不同的铬空位诱导激发。这些空位诱导激发的能量尺度为几十毫电子伏特，且为二重简并，其中位于64 cm⁻¹的最低激发态尖锐且对沿易轴方向的外磁场敏感，尤其在6T附近的自旋翻转区域，该模式从64 cm⁻¹软化至27 cm⁻¹。基于缺陷超胞的第一性原理计算，我们将64 cm⁻¹处的模式解释为铬空位态内局域磁矩的局域磁激发。我们的结果表明，Cr₂O₃中的磁性缺陷态具有量子应用潜力。
英文摘要
Point defects have been successfully utilized in various quantum technologies, serving as quantum qubits for quantum computation, single-photon emitters for quantum communication, and nanoscale sensors for quantum metrology. However, their further development faces key challenges, particularly in discovering and exploring suitable defect-host systems that meet the necessary criteria for quantum applications. Here, using polarization-resolved Raman spectroscopy and terahertz absorption spectroscopy, we discover three distinct chromium-vacancy-induced excitations in the uniaxial antiferromagnetic insulator, Cr$_2$O$_3$. These vacancy-induced excitations have an energy scale of a few tens of millielectronvolts and are twofold degenerate, and the lowest one at 64 $cm^{-1}$ is sharp and sensitive to the external magnetic field along the easy-axis direction, particularly close to the spin-flop regime around 6T, where the mode softens from 64 to 27$cm^{-1}$. Based on the defect supercell first-principles calculations, we interpret the mode at 64 $cm^{-1}$ as a local magnetic excitation of the local moment within the chromium vacancy state. Our results establish that the magnetic defect states in Cr$_2$O$_3$ have potential for quantum applications.
Comments37 pages, 13 figures
