AI 中文总结
研究赤铁矿在GHz到THz频率范围的非互易特性，用微观自旋哈密顿量等方法，发现电导率张量在特定能隙有频率峰值且可调节，倾斜磁矩导致非零霍尔电导率，还探讨其在非互易环行器设计的应用。
AI 中文摘要
我们研究了倾斜易平面反铁磁相中的氧化铁α-Fe₂O₃（赤铁矿）的非互易特性，特别是在GHz到THz频率范围内。首先，使用微观自旋哈密顿量，我们获得了由Dzyaloshinskii-Moriya相互作用（DMI）诱导倾斜的正确经典基态。使用线性自旋波理论模拟了磁振子谱。然后，我们使用线性响应计算极化率和亚能隙光导率。我们发现，电导率张量在零动量磁振子能隙处包含频率峰值，其大小约为0.1 meV，可由DMI和局域各向异性自旋相互作用调节。此外，我们表明，倾斜诱导的净磁矩m代表了系统有效时间反演对称性破缺和非互易性的一种度量：有限的m会导致非零的霍尔电导率。最后，我们通过使用电导率作为输入计算非互易环行器传输幅度，讨论了赤铁矿在非互易环行器设计中的潜在应用。
英文摘要
We study the non-reciprocal properties of the iron oxide $α$-Fe$_2$O$_3$ (hematite) in the canted easy-plane antiferromagnetic phase, specifically in the GHz to THz frequency range. First, using the the microscopic spin Hamiltonian, we obtain the correct classical ground state where the canting is induced by the Dzyaloshinskii-Moriya interactions (DMI). The magnon spectrum is simulated using linear spin wave theory. We then compute the polarizability and the sub-gap optical conductivities using linear response. We find that the conductivity tensor contains frequency peaks at the zero momentum magnon gaps of order $0.1~$meV which can be tuned by the DMI and on-site anisotropic spin interactions. Furthermore, we show that the canting-induced net magnetic moment $\mathbf{m}$ represents a measure for the effective time-reversal-symmetry breaking and non-reciprocity of the system: a finite $\mathbf{m}$ results in a non-zero Hall conductivity. Finally, we discuss the prospective application of hematite in non-reciprocal circulator design, by computing the non-reciprocal circulator transmission amplitude using the conductivities as input.
Comments10 pages, 7 figures
