Department of Physics

Abstract: Information and communications technology is predicted to account for 10% to 20% of the world’s power consumption within a decade. Alleviating this rise in power consumption requires rethinking the way we electronically process and store information. One promising route to develop energy-efficient storage/memory uses spintronic devices such as magnetic tunnel junctions in conjunction with traditional CMOS devices. In this talk, I will discuss a well-known write mechanism for such magnetic memories whereby a charge current manipulates a ferromagnetic layer’s magnetization through spin-orbit coupling.  This mechanism, known as spin-orbit torque, is promising because it involves a transfer of angular momentum from the atomic lattice—a virtually infinite source of angular momentum—to the magnetic order. We review the traditional spin-orbit torque mechanisms and then show that novel interfacial and bulk mechanisms are needed to explain recent experiments. These novel mechanisms include interface generated spin currents, and intrinsic and extrinsic spin current generation in ferromagnets and antiferromagnets. Shedding light on the nature of spin-orbit torque creates exciting new possibilities for current-controlled magnetization dynamics with attractive applications for information processing.

Short Biography: Dr. Vivek Amin is an Assistant Professor in the Department of Physics at Indiana University Purdue University, Indianapolis (IUPUI). He received a B.S. in Electrical Engineering from The University of Texas at Austin and a Ph.D. in Physics from Texas A&M University.  Prior to joining IUPUI, he worked as a postdoc and a research scientist with a joint position at the National Institute of Standards and Technology, Gaithersburg and the University of Maryland, College Park. Prof. Amin uses computational and analytical methods to study electronic transport in condensed matter systems, with focus on spintronics, quantum materials, and neuromorphic computing.