Hysteresis regime in the operation of a dual-free-layer spin-torque nano-oscillator with out-of-plane counter-precessing magnetic moments

摘要

We studied the operation of a dual-free-layer (DFL) spin-torque nano-oscillator (STNO) and demonstrated that in a practically interesting regime when the magnetizations of the two free layers (FLs) precess in opposite directions along large-angle out-of-plane trajectories, thus doubling the generation frequency, the operation of the DFL STNO is strongly hysteretic as a function of a bias dc current. The stable magnetization dynamics starts at a rather large magnitude of the bias dc current density Jdc>Jthhigh when the bias current is increased, but the regime of stable counter-precession of the FLs persists till rather low magnitudes of the bias dc current density Jthlow