Spin Hall effects in mesoscopic Pt films with high resistivity

Abstract

Abstract:The energy efficiency of the spin Hall effects (SHE) can be enhanced if the electrical conductivity is decreased without sacrificing the spin Hall conductivity. The resistivity of Pt films can be increased to 150 -300 µΩ•cm by mesoscopic lateral confinement, thereby decreasing the conductivity. The SHE and inverse spin Hall effects (ISHE) in these mesoscopic Pt films are explored at 10 K by using the nonlocal spin injection/detection method. All relevant physical quantities are determined in-situ on the same substrate, and a quantitative approach is developed to characterize all processes effectively. Extensive measurements with various Pt thickness values reveal an upper limit for the Pt spin diffusion length:≤ 0.8 nm. The average product of and the Pt spin Hall angle is substantial: = (0.142 ± 0.040) nm for 4 nm thick Pt, though a gradual decrease is observed at larger Pt thickness. The results suggest enhanced spin Hall effects in resistive mesoscopic Pt films.

Prediction of inverse spin Hall devices based on the direct injection of carriers in L-valley of GaAs

“…Understanding the electron spin dynamics in different materials under divergent experimental conditions has been one of the most emerging topics of research over last one and half decade [1][2][3]. A complete knowledge of electron spin dynamics is critically important for the manifestation of spin to charge inter-conversion (SCI) phenomenon which arises from the relativistic spin-orbit coupling of electronic spin with crystal electric field [4][5][6]. SCI phenomenon is utilized for the generation of dissipation less carrier flow and is closely associated with the development of fast and economically viable spintronic devices [7,8].…”