Breaking the electromagnetic boundaries in ferromagnetic materials

Researchers at Transformative Quantum Technology at the University of Waterloo are accelerating towards fully electrical spintronics.

By Lubaba Hoque, Transformative Quantum Technologies

The ability to manipulate magnetization is highly desirable in real world applications such as data storage and medical imaging. For instance, within the aerospace, defence and automotive industries, Magnetoresistive Random Access Memories (MRAM’s) are widely used for information storage. However, the manipulation of spin state in ferromagnetic materials is often not very energy efficient. In recent years, Spin-Orbit Torque (SOT), has received attention for its ability to manipulate the spin states in a more localized and energy efficient manner. Still, scalability remains a challenge.

In MRAM’s, the perpendicular configuration of spin elements makes them denser and often requires additional magnetic fields to manipulate the spins to the desired state (up or down). Conventional SOT can readily switch spin elements in the in-plane directions, but not up or down. To switch a perpendicular spin element, an external field is required to tilt it to the up or down position. This in turn adds additional overhead and accidental disturbances to neighbouring bits.

Transformative Quantum Technologies (TQT) supported researchers Dr. Guo-Xing Miao, Institute for Quantum Computing (IQC) Faculty and Professor, Department of Electrical and Computer Engineering, and his group have demonstrated a way to bypass the need for additional magnetic fields. The researchers have shown that coupled with a low symmetry system, the fully electric SOT allows bias-field free, deterministic switching of the perpendicular spin elements to the desired state. This is done by breaking all-in plane symmetries, which conventional SOT cannot do without the use of external magnetic fields.