Deterministic Switching of the Néel Vector by Asymmetric Spin Torque

Area of Science:

• Spintronics
• Condensed Matter Physics
• Materials Science

Background:

• The Néel vector, an order parameter for collinear antiferromagnets, is key for information encoding in antiferromagnetic (AFM) spintronic devices.
• Deterministic switching of the Néel vector is essential for write-in operations but remains a significant challenge in AFM spintronics.

Purpose of the Study:

• To demonstrate a general mechanism for achieving deterministic Néel vector switching in collinear antiferromagnets.
• To explore the potential of current-induced spin torque for enabling efficient writing in AFM spintronics.

Main Methods:

• Analytical derivation and macro-spin simulations were employed to investigate Néel vector switching.
• The study focused on current-induced spin torque arising from non-identical spin accumulations between opposite sublattices.

Main Results:

• Néel vector switching is generally achievable via current-induced spin torque when sublattice spin accumulations are non-identical, a common scenario in AFM films.
• An asymmetric spin torque, featuring cooperative contributions from field-like and damping-like components, leads to distinct Néel vector dynamics.
• The stabilized static states enable versatile field-free switching strategies, adapting established techniques from ferromagnetic spintronics.

Conclusions:

• A general mechanism for current-induced Néel vector switching is established, applicable to all collinear antiferromagnets.
• This work paves the way for realizing efficient writing operations in antiferromagnetic spintronics.