Controlling dynamical mode coupling in magnetic nano-oscillators is essential to improving their microwave spectral properties for rf applications and neuromorphic computing. Progress here is held back by the lack of a suitable platform that provides controlled coupling. This study experimentally demonstrates control of dynamical mode coupling in spin Hall nano-oscillators with perpendicular magnetic anisotropy, by means of temperature, excitation current, and magnetic field. It is established that mode coupling in this system is dominated by thermal magnon-mediated scattering, suggesting fresh approaches to engineering device properties suitable for the desired applications.

In collaboration with Prof. Di Wu’s group in our Department,We published a paper entitled “Enhanced spin accumulation in metallic bilayers with opposite spin Hall angles” in PRB [Physical Review B 99, 174406 (2019)].Spin accumulation can be generated via the spin Hall effect in a nonmagnetic material. It was previously found that spin accumulation and associated spintronic phenomena are attenuated in metallic bilayer with opposite spin angles. Here, we investigate the spin Hall magnetoresistance (SMR) in $\mathrm{Pt}/Y_{3}F{e}_5{O}_{12}$ (YIG) with a thin W capping layer, in which W and Pt have opposite spin Hall angles. We find an increase of the SMR ratio with a W capping layer thinner than 1.0 nm. According to theoretical simulation, we attribute this phenomenon to the enhancement of the spin accumulation at the Pt/YIG interface, opposite to previous observations. Our findings provide a new approach for generating spin accumulation and associated pure spin current intensity for spintronic applications

We published a paper entitled “Controlling the Spectral Characteristics of a Spin-Current Auto-Oscillator with an Electric Field” in PR APPLIED [Physical Review Applied 8, 021001 (2017)]. In this work, we demonstrated that the characteristic currents required for the excitation, the intensity and the spectral characteristics of the generated magnetic nano-oscillation can be tuned by the gate voltage, and the effect of electrostatic gating becomes enhanced in the strongly nonlinear oscillation regime. Electric-field modulation of the current-induced magnetization oscillations and spin waves demonstrated in this work can be utilized for frequency mixing, synchronization, and in logic gates in spin wave-based electronic (magnonic) devices.