Bidirectional switching assisted by interlayer exchange coupling in asymmetric magnetic tunnel junctions

Area of Science:

• Spintronics
• Condensed Matter Physics
• Materials Science

Background:

• Perpendicular magnetic tunnel junctions (p-MTJs) are key components in magnetic memory devices.
• Controlling magnetic switching with low energy consumption is a critical challenge.
• Spin transfer torque and magnetic anisotropy are established methods for switching.

Purpose of the Study:

• To investigate the combined effects of spin transfer torque, voltage modulation of interlayer exchange coupling, and magnetic anisotropy on p-MTJ switching.
• To explore a novel mechanism for reducing switching energy in asymmetric p-MTJs.
• To analyze the feasibility of switching solely through interlayer exchange coupling modulation.

Main Methods:

• Theoretical modeling of p-MTJ switching dynamics.
• Analysis of voltage-dependent interlayer exchange coupling in asymmetric structures.
• Simulation of spin transfer torque and anisotropy effects.

Main Results:

• A linear-in-voltage dependence of interlayer exchange coupling was identified in asymmetric p-MTJs.
• This voltage modulation effectively lowers the perpendicular anisotropy barrier for both voltage polarities.
• The proposed mechanism significantly reduces the critical switching current and effective activation energy.

Conclusions:

• Voltage modulation of interlayer exchange coupling offers a promising pathway to reduce switching energy in p-MTJs.
• This approach can complement or potentially replace traditional spin transfer torque methods.
• Switching via interlayer exchange coupling alone is a viable possibility under specific conditions.