Efficient Spin Torques in Antiferromagnetic CoO/Pt Quantified by Comparing Field- and Current-Induced Switching

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Antiferromagnetic materials offer potential for high-density, low-power spintronic devices.
• Controlling the Néel vector in insulators with electrical currents remains a significant challenge.
• Collinear antiferromagnets like Cobalt Oxide (CoO) exhibit unique magnetic properties.

Purpose of the Study:

• To achieve and electrically characterize current-induced switching in insulating antiferromagnetic CoO/Pt heterostructures.
• To investigate the switching mechanism and quantify the efficiency of current-induced torques.
• To explore the potential of CoO/Pt for advanced spintronic applications.

Main Methods:

• Electrical measurements utilizing spin Hall magnetoresistance (SMR) in CoO/Pt bilayers.
• Application of current pulses and external magnetic fields to induce switching.
• Confirmation of switching via magnetic field-induced spin-flop transitions in CoO.
• Quantification of current-induced torques and estimation of current-field equivalence.

Main Results:

• Successful demonstration of current-induced switching in collinear insulating antiferromagnetic CoO/Pt.
• Electrical characterization via SMR confirmed the switching behavior.
• A current-field equivalence ratio of 4×10⁻¹¹ T A⁻¹ m² was estimated.
• The Néel vector's final state (n⊥j) suggests a thermomagnetoelastic switching mechanism.

Conclusions:

• Current-induced switching is achievable in insulating antiferromagnetic CoO/Pt.
• The switching mechanism is consistent with thermomagnetoelastic effects, driven by a negative magnetoelastic constant in CoO.
• This work paves the way for electrical control of insulating antiferromagnets in spintronic devices.