MnO中由脉冲太赫兹激发驱动的相干反铁磁共振
Coherent antiferromagnetic resonance in MnO driven by impulsive terahertz excitation
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory（斯坦福材料能源科学研究所，SLAC国家加速器实验室）
- University of Iowa（爱荷华大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过脉冲太赫兹激发在单晶MnO中实现了相干反铁磁共振的时域检测，发现其双折射信号弱于NiO，归因于弱自旋-轨道磁光耦合，表明激发与检测由不同微观机制主导。
AI中文摘要：
反铁磁体（AFMs）因其固有的快速自旋动力学和消失的净磁化强度，为超快信息处理提供了有前景的平台。然而，要实现这一潜力，需要理解太赫兹场如何激发相干磁振子，以及由此产生的自旋运动如何转化为光学信号。在此，我们报道了在单晶氧化锰（II）中进行的脉冲太赫兹（THz）激发和反铁磁共振（AFMR）的时域检测。时间分辨的双折射测量揭示了反铁磁相中长寿命的相干自旋振荡。随着温度升高接近奈尔温度，共振软化并变得强烈阻尼。尽管激发行为相似，但在MnO中检测到的双折射明显弱于NiO。我们将这种抑制的光学可见性归因于轨道单重态、高自旋Mn$^{2+}$的弱自旋-轨道介导的磁光耦合。这些结果表明，相干磁振子激发及其光学检测受不同的微观相互作用支配。
英文摘要：
Antiferromagnets (AFMs) offer a promising platform for ultrafast information processing owing to their intrinsically fast spin dynamics and vanishing net magnetization. Realizing this potential, however, requires understanding how terahertz fields excite coherent magnons and how the resulting spin motion is transduced into an optical signal. Here we report impulsive terahertz (THz) excitation and time-domain detection of the antiferromagnetic resonance (AFMR) in single-crystal manganese(II) oxide. Time-resolved birefringence measurements reveal long-lived coherent spin oscillations in the AFM phase. The resonance softens and becomes strongly damped upon warming toward the Néel temperature. Despite this similar excitation behavior, the detected birefringence in MnO is markedly weaker than in NiO. We associate this suppressed optical visibility with the weak spin--orbit-mediated magneto-optical coupling of orbital-singlet, high-spin Mn$^{2+}$. These results demonstrate that coherent magnon excitation and its optical detection are governed by distinct microscopic interactions.
