标题： 热噪声对非共线反铁磁体Mn3Sn场驱动动力学的影响 显示英文标题

标题： Influence of thermal noise on the field-driven dynamics of the non-collinear antiferromagnet Mn3Sn

摘要： $\mathrm{Mn_3Sn}(0\overline{1}\overline{1}0)[0001]$在外延生长在$\mathrm{MgO}(110)[001]$上时会经历拉伸应变，因此能量景观从六重对称性变为两重对称性。外部磁场进一步破坏对称性，并改变\textcolor{black}{产生的能量景观对} 与易轴方向的相对关系。 \textcolor{black}{在存在热噪声的情况下，} 磁四极矩在\textcolor{black}{一种应变的Mn$_3$Sn薄膜} 中的弛豫由四种不同的逃逸过程组成，涉及能量景观中的两个鞍点和两个平衡状态。 在这里，我们应用谐波过渡态理论，推导出井间逃逸时间和四极矩弛豫时间的解析表达式，两者均受外部对称性破缺磁场和中等至高阻尼区域中的有限热噪声影响。 解析预测与基于耦合 LLG 方程的全面数值模拟结果高度一致。 这里呈现的结果对于实现 Mn$_3$Sn 在随机数生成和概率计算中的应用至关重要。 显示英文摘要

摘要： $\mathrm{Mn_3Sn}(0\overline{1}\overline{1}0)[0001]$ experiences a tensile strain when grown epitaxially on $\mathrm{MgO}(110)[001]$, and thus the energy landscape changes from six-fold symmetry to two-fold symmetry. External magnetic field further breaks the symmetry and the \textcolor{black}{resulting energy landscape is sensitive to} the field orientation relative to the easy axis. \textcolor{black}{In the presence of thermal noise,} the relaxation of the magnetic octupole moment in \textcolor{black}{a strained Mn$_3$Sn film} is composed of four distinct escape processes involving the two saddle points and two equilibrium states in the energy landscape. Here, we apply harmonic transition-state theory to derive analytical expressions for the inter-well escape time and octupole moment relaxation time, both influenced by an external symmetry-breaking magnetic field and finite thermal noise in the intermediate-to-high damping regime. The analytical predictions are in strong agreement with comprehensive numerical simulations based on coupled LLG equations. The results presented here are crucial toward realizing Mn$_3$Sn's applications in random number generation and probabilistic computing.