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Yearly Archives: 2019

Observation of topological Hall effect in antiferromagnetic FeRh film

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In collaboration with Prof. Dunhui Wang’s group in our physical department, we published a paper entitled “Observation of topological Hall effect in antiferromagnetic FeRh film”in APL [Applied Physical Letters 115, 022404 (2019)]. Noncollinear magnetic structures can give rise to peculiar Hall effects and hold promise for next-generation spintronic devices. In this work, we report the observation of the topological Hall effect (THE) through electrical transport measurements in antiferromagnetic B2-ordered FeRh thin films grown by sputtering techniques on a MgO (001) substrate. Our results opens the possibility to discover the topological Hall effect in centrosymmetric antiferromagnets in contrast to the widely reported B20-type chiral magnets.

New progress in the dynamical mode coupling and coherence in a nano-oscillator

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 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.

Paper published in PRB in collaboration with Prof. Di Wu’s group

PhysRevB.99In 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 Pt/Y3Fe5O12 (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