Spin-Torque Ferromagnetic Resonance (ST-FMR)

ST-FMR: Spin-Torque Resonance

Macrospin Landau-Lifshitz-Gilbert equation with Slonczewski spin-transfer torque. An AC current drives magnetization precession; resonance at ω_FMR.

dm/dt = -γm×H_eff + α m×dm/dt + τ_ST

Applied field H (mT): 50 Drive freq ω/ω₀: 1.00 Damping α: 0.02 Spin torque J: 0.10

Sweep field → observe resonance absorption peak. Spin torque can compensate damping → auto-oscillation above threshold.