479 research outputs found
Intrinsic Spin Hall Conductivity of MoTe2 and WTe2 Semimetals
We report a comprehensive study on the intrinsic spin Hall conductivity (SHC)
of semimetals MoTe2 and WTe2 by ab initio calculation. Large SHC and desirable
spin Hall angles have been discovered, due to the strong spin orbit coupling
effect and low charge conductivity in semimetals. Diverse anisotropic SHC
values, attributed to the unusual reduced-symmetry crystalline structure, have
been revealed. We report an effective method on SHC optimization by electron
doping, and exhibit the mechanism of SHC variation respect to the energy
shifting by the spin Berry curvature. Our work provides insights into the
realization of strong spin Hall effects in 2D systems
Spin-Cherenkov effect in a magnetic nanostrip with interfacial Dzyaloshinskii-Moriya interaction
Spin-Cherenkov effect enables strong excitations of spin waves (SWs) with
nonlinear wave dispersions. The Dzyaloshinskii-Moriya interaction (DMI) results
in anisotropy and nonreciprocity of SWs propagation. In this work, we study the
effect of the interfacial DMI on SW Cherenkov excitations in permalloy
thin-film strips within the framework of micromagnetism. By performing
micromagnetic simulations, it is shown that coherent SWs are excited when the
velocity of a moving magnetic source exceeds the propagation velocity of the
SWs. Moreover, the threshold velocity of the moving magnetic source with finite
DMI can be reduced compared to the case of zero DMI. It thereby provides a
promising route towards efficient SW generation and propagation, with potential
applications in spintronic and magnonic devices.Comment: 6 pages, 5 figures. To be published in Scientific Report
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