Analytical description of ballistic spin currents and torques in magnetic tunnel junctions - CEA - Commissariat à l’énergie atomique et aux énergies alternatives Access content directly
Journal Articles Physical Review B: Condensed Matter and Materials Physics (1998-2015) Year : 2015

Analytical description of ballistic spin currents and torques in magnetic tunnel junctions

Abstract

In this work we demonstrate explicit analytical expressions for both charge and spin currents which constitute the 2x2 spinor in magnetic tunnel junctions with non collinear magnetizations under applied voltage. We demonstrate that spin/charge currents and spin transfer torques are all explicitly expressed through only three irreducible quantities, without further approximations. From the expressions derived, it is shown that in the case of a symmetric tunnel junction, the bias dependence is conventional and in the presence of asymmetries, additional odd parity terms appear. Furthermore, the conditions and mechanisms of deviation from the conventional sine angular dependence of both spin currents and spin torques are evidenced and discussed. Finally, it is shown in the thick barrier approximation that all tunneling transport quantities can be expressed in an extremely simplified form via Slonczewski spin polarizations and newly introduced effective spin averaged interfacial transmission probabilities and effective out-of-plane polarizations at both interfaces. It is proven that the latter plays a key role in origin of perpendicular spin torque as well as for angular dependence character of all spin and charge transport considered. It is then demonstrated directly that for any applied voltage, the parallel component of spin current at the FM/I interface is expressed via collinear longitudinal spin current components.
Fichier principal
Vignette du fichier
chs1.pdf (1.43 Mo) Télécharger le fichier
Origin Files produced by the author(s)

Dates and versions

cea-01072994 , version 1 (01-02-2021)

Identifiers

Cite

M. Chshiev, A. Manchon, A. Kalitsov, N. Ryzhanova, A. Vedyayev, et al.. Analytical description of ballistic spin currents and torques in magnetic tunnel junctions. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2015, 92 (10), pp.104422. ⟨10.1103/PhysRevB.92.104422⟩. ⟨cea-01072994⟩
207 View
75 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More