First-Principles Quantum Transport Modeling of Spin-Transfer and Spin-Orbit Torques in Magnetic Multilayers

This chapter discusses the spin-transfer effect, which is described as the transfer of the spin angular momentum between the conduction electrons and the magnetization of the ferromagnet that occurs due to the conservation of the spin angular momentum. L. Berger, who introduced the concept in 1984, considered the exchange interaction between the conduction electron and the localized magnetic moment, and predicted that a magnetic domain wall can be moved by flowing the spin current. The spin-transfer effect was brought into the limelight by the progress in microfabrication techniques and the discovery of the giant magnetoresistance effect in magnetic multilayers. Berger, at the same time, separately studied the spin-transfer torque in a system similar to Slonczewski’s magnetic multilayered system and predicted spontaneous magnetization precession.

Download Full-text

Field-free and sub-ns magnetization switching of magnetic tunnel junctions by combining spin-transfer torque and spin–orbit torque

Applied Physics Letters ◽

10.1063/5.0039061 ◽

2021 ◽

Vol 118 (9) ◽

pp. 092406

Author(s):

Chaoliang Zhang ◽

Yutaro Takeuchi ◽

Shunsuke Fukami ◽

Hideo Ohno

Keyword(s):

Tunnel Junctions ◽

Magnetic Tunnel Junctions ◽

Spin Transfer Torque ◽

Spin Transfer ◽

Spin Orbit ◽

Magnetization Switching

Download Full-text

First principles calculations of the structural, electronic, magnetic, and thermodynamic properties of the Nd2MgGe2 and Gd2MgGe2 intermetallic compounds

Scientific Reports ◽

10.1038/s41598-021-89042-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

S. Menouer ◽

O. Miloud Abid ◽

A. Benzair ◽

A. Yakoubi ◽

H. Khachai ◽

...

Keyword(s):

Thermal Conductivity ◽

Thermodynamic Properties ◽

Ground State ◽

First Principles ◽

Essential Role ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Rare Earth Compounds ◽

First Principles Calculations ◽

Antiferromagnetic Ground State

AbstractIn recent years the intermetallic ternary RE2MgGe2 (RE = rare earth) compounds attract interest in a variety of technological areas. We therefore investigate in the present work the structural, electronic, magnetic, and thermodynamic properties of Nd2MgGe2 and Gd2MgGe2. Spin–orbit coupling is found to play an essential role in realizing the antiferromagnetic ground state observed in experiments. Both materials show metallicity and application of a Debye-Slater model demonstrates low thermal conductivity and little effects of the RE atom on the thermodynamic behavior.

Download Full-text

Spin-orbit torques in strained PtMnSb from first principles

Physical Review B ◽

10.1103/physrevb.103.224414 ◽

2021 ◽

Vol 103 (22) ◽

Author(s):

Frank Freimuth ◽

Stefan Blügel ◽

Yuriy Mokrousov

Keyword(s):

First Principles ◽

Spin Orbit

Download Full-text

First principles study of the spin–orbit interaction effect on the opto-electric properties of lead telluride

Materials Science in Semiconductor Processing ◽

10.1016/j.mssp.2015.08.032 ◽

2016 ◽

Vol 41 ◽

pp. 83-88 ◽

Cited By ~ 4

Author(s):

Bahroz Rashid ◽

Muhammad Hilal ◽

Shah Haider Khan ◽

Afzal Khan

Keyword(s):

Interaction Effect ◽

First Principles ◽

Lead Telluride ◽

Orbit Interaction ◽

Electric Properties ◽

Spin Orbit ◽

Spin Orbit Interaction ◽

First Principles Study

Download Full-text

Current-induced spin–orbit torques

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2010.0336 ◽

2011 ◽

Vol 369 (1948) ◽

pp. 3175-3197 ◽

Cited By ~ 204

Author(s):

Pietro Gambardella ◽

Ioan Mihai Miron

Keyword(s):

Angular Momentum ◽

Exchange Coupling ◽

Spin Transfer Torque ◽

Spin Transfer ◽

Spin Torque ◽

Inversion Symmetry ◽

Spin Orbit ◽

Great Flexibility ◽

Combined Action ◽

Proper Material

The ability to reverse the magnetization of nanomagnets by current injection has attracted increased attention ever since the spin-transfer torque mechanism was predicted in 1996. In this paper, we review the basic theoretical and experimental arguments supporting a novel current-induced spin torque mechanism taking place in ferromagnetic (FM) materials. This effect, hereafter named spin–orbit (SO) torque, is produced by the flow of an electric current in a crystalline structure lacking inversion symmetry, which transfers orbital angular momentum from the lattice to the spin system owing to the combined action of SO and exchange coupling. SO torques are found to be prominent in both FM metal and semiconducting systems, allowing for great flexibility in adjusting their orientation and magnitude by proper material engineering. Further directions of research in this field are briefly outlined.

Download Full-text