Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 63: Spin: Transport, Orbitronics and Hall Effects III
MA 63.3: Vortrag
Freitag, 20. März 2020, 10:00–10:15, HSZ 403
The spin Hall effect in β-W and interstitial impurities — •O. L. W. McHugh1, M. Gradhand1, W. F. Goh2, and D. A. Stewart3 — 1University of Bristol, UK — 2University of California at Davis, Davis, CA, USA — 3Western Digital Corporation, San Jose, CA, USA
One of the best metals to convert charge into spin current via the spin Hall effect (SHE) [1] is β-W. Its structural stabilization requires doping with O and N [2] atoms. In addition, increasing the impurity concentration enhances its SHA [3]. The exact mechanism of this enhancement is unknown. We present ab-initio calculations to investigate these impurities for both α-W (bcc) and β-W on both the intrinsic and the extrinsic mechanism. We compare the PAOFlow[4] code using the Kubo formula with the semi classical description via the Berry curvature as implemented in the KKR [5]. For further investigations in impurities, as well as structural relaxation, we rely on the PAOFlow for the intrinsic and the KKR-Boltzmann method for the extrinsic contribution. We found good agreement to experiment, highlighting that for β-W the reduction of the charge conductivity is driving the effective charge to spin conversion. Beyond stabilization, the effect of impurities is small and a quantitative analysis will be presented.
[1] C.-F. Pai et al., Appl. Phys. Letters, 101(12) (2012)
[2] J. Liu, Doctoral Theses, Columbia University, NY, USA (2016)
[3] K.-U. Demasius et al., Nat. Comm., 7, 10664 (2016)
[4] M. Nardelli et al., Comp. Mat. Science 143, 462-472 (2018)
[5] M. Gradhand et al., Phys. Rev. B, 84, 075113 (2011)