Voltage Control of Magnetism: Low-Power Spintronics

Conventional spintronics-based memory devices use an electrical current in elegant ways to control the direction and dynamics of electrons’ spin, yet at higher energy cost and lower device endurance. Therefore, keeping pace with the growing demand for faster, smaller, and ultra-low-power electronic devices, research in the field of voltage control of magnetism has intensified recently with the promises to deliver ultra-low-power operating non-volatile memory solutions for next-generation computing systems. Here, we present our recent efforts in voltage-controlled magnetism via different approaches; voltage-controlled magnetic anisotropy (VCMA), voltage-controlled exchange coupling (VCEC), and multiferroic-based magnetoelectric coupling (MEC) for spintronics applications. These studies yielded several new findings. Large tunability of perpendicular magnetic anisotropy (PMA) has been achieved with the insertion of the Pt layer at the MgO/Ferromagnet interface. The modulation of the interlayer exchange coupling with the Ru spacer layer has been demonstrated by using non-ionic liquid gating such as MgO. Besides this, we have also shown the modulation of the magnetism by utilizing the magneto-electric coupling effect in a bismuth ferrite-based multiferroic system. These efforts provide several routes to modulate the resistance states of spintronic devices at low power and bring forth a vast playground to develop next-generation energy-efficient computing devices.