Relativistic torques induced by currents in magnetic materials: physics and experiments

Area of Science:

• Spintronics
• Condensed Matter Physics
• Materials Science

Background:

• Current-induced torques are relativistic phenomena in ferromagnetic (FM)/non-magnetic (NM) heterostructures.
• Large spin-orbit coupling (SOC) and high-quality interfaces are crucial for observing these torques.
• Understanding these torques reveals the link between magnetization and spin transport.

Purpose of the Study:

• To provide an insight into the physics of current-induced torques in FM/NM systems.
• To emphasize experimental observations of these torques.
• To review the current understanding and future challenges in this field.

Main Methods:

• Review of experimental observations of current-induced torques.
• Discussion of the spin Hall effect in NM layers with large SOC.
• Analysis of the reciprocal process where changing magnetization generates spin current.

Main Results:

• Current-induced torques can reverse magnetization in FM/NM systems with large SOC.
• The spin Hall effect in the NM layer is a key mechanism.
• A reciprocal spin current generation from changing magnetization is observed.

Conclusions:

• Current-induced torques are vital for understanding magnetization dynamics and spin transport.
• This phenomenon holds significant promise for advancing magnetic recording technologies and memory devices.
• Further research is needed to fully explore the potential of spintronics in this area.