Regensburg 2016 – scientific programme
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MA: Fachverband Magnetismus
MA 35: Spin dependent Transport Phenomena
MA 35.1: Talk
Wednesday, March 9, 2016, 15:00–15:15, H33
Ab initio theory of spin-orbitronics transport effects in disordered Heusler and antiferromagnetic alloys — •Libor Šmejkal1,2, Karel Carva2, Ilja Turek2, and Tomáš Jungwirth1 — 1IoP, ASCR, Cukrovarnicka 10/112, CZ-16253 Prague, Czech Republic — 2DCMP, Charles University, Ke Karlovu 5, CZ-12116 Prague, Czech Republic
We present unified fully relativistic tight-binding linear-muffin-tin-orbital framework for ab initio calculation of spin-orbit torque, anomalous Hall effect, and anisotropic magnetoresistance (AMR) in disordered systems based on coherent potential approximation and Bastin formula.[1-2] We compare our implementation with non-equilibrium Green functions technique, and FLEUR ab initio package.[2-3] Within the developed formalism are calculated aforementioned effects in materials promising for room temperature spin-orbitronics applications (Heusler alloys XMnSb, non-collinear antiferromagnets (AFM) XMn3, and AFM CuMnAs). Finally, the physics gathered from the first-principles calculations is discussed. For instance, the results provide a microscopic theory confirmation of the experimentally measured AMR signals in Ni-rich NiMnSb thin films.[3] AMR has a negative sign and a magnitude reaching 1% for current along the [110] direction, while a strong crystalline term yield an almost perfect cancellation of the AMR for current along the [100] direction.
[1]I. Turek et al., Phys. Rev. B 89 (2014)
[2] F. Freimuth et al., Phys. Rev. B 92 (2015)
[3] C. Ciccarelli et al., eprint arXiv:1510.03356 (2015)