Year: 2026
Type: preprint
Abstract: We study helicity-selective antiferromagnetic resonance in an antiferromagnetic-insulator/nonmagnetic-metal junction with sublattice-dependent damping and spin-orbit torque. By formulating the linearized Landau--Lifshitz--Gilbert equation as a 2x2 non-Hermitian eigenvalue problem, we analyze the complex resonance frequencies and the stability threshold, using MnF$_2$ parameters as a representative example of a uniaxial antiferromagnet. We show that the absorption is strongly enhanced near the stability threshold, where one helicity mode becomes weakly damped, leading to linewidth narrowing and pronounced helicity selectivity in the sub-THz regime. The selected helicity can be switched by reversing the current direction, which reverses the spin-orbit torque acting on the interfacial sublattice. These results identify stability-threshold control as a design principle for electrically tunable helicity-selective antiferromagnetic resonance in uniaxial antiferromagnets.
Source: arXiv (Cornell University)
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: ナノ構造における光角運動量の電子線による超分解能解析と制御, Advancement of Antiferromagnetic Photo-Spintronics, G423850566, G4300652936, Novel plasmonic optics using non-Hermitian photonics, 非エルミートプラズモニクスによる量子バイオセンシング, Theoretical Study of Chirality-Induced Spin Transport Based on Spin-Microrotation Coupling, Reconfigurable topological nanophotonics
OpenAlex ID: W7167797881