Research

We theoretically investigate condensed matter systems where the spin and magnetic moment of electrons can be used to process or store information. This field of study, known as spintronics, ushered in a revolution in magnetic storage capacity by vastly improving the sensitivity of hard disk read heads. Spintronic devices now promise a wide range of applications, from storing binary information in next-generation magnetic memories to mimicking properties of neurons and synapses for artificial intelligence applications.

We are currently identifying and characterizing the physical mechanisms underlying spin-orbit torque, which is a potentially low-power way to write magnetic memories. Spin-orbit torques occur when electrons carrying current take angular momentum from atomic nuclei and transfer that angular momentum to electrons carrying magnetic order. In addition to investigating spin-orbit torque in “traditional” materials like heavy metals and transition metal ferromagnets, we are exploring how “quantum” materials like topological insulators and low-dimensional materials can enhance spin-orbit torque efficiency and create new functionality. Finally, we are applying what we learn about these systems to design and simulate neural networks driven by spin-orbit torque, which could operate at lower power than traditional, fully CMOS-based neural networks.

Education

• B.S. Electrical Engineering, University of Texas at Austin, 2006
• Ph.D. Physics, Texas A&M University, 2014

Publications & Professional Activity

• Yi Li, W. Cao, V. P. Amin, Z. Zhang, J. Gibbons, J. Sklenar, J. Pearson, P. M. Haney, M. D. Stiles, W. E. Bailey, V. Novosad, A. Hoffmann, and W. Zhang, Coherent spin pumping in a strongly coupled magnon-magnon hybrid system, Phys. Rev. Lett. 124, 117202 (2020)
• W. Wang*, T. Wang*, V. P. Amin, Y. Wang, A. Radhakrishnan, A. Davidson, S. R. Allen, T. J. Silva, H. Ohldag, D. Balzar, B. L. Zink, P. M. Haney, J. Q. Xiao, D. G. Cahill, V. O. Lorenz, and X. Fan, Anomalous Spin-Orbit Torques in Magnetic Single-Layer Films, Nature Nanotechnology, 14, 819-824 (2019)
• V. P. Amin, J. Li, M. D. Stiles, and P. M. Haney, Intrinsic Spin Currents in Ferromagnets, Phys. Rev. B 99, 220405(R) (2019)
• V. P. Amin, J. Zemen, and M. D. Stiles, Interface generated spin currents, Phys. Rev. Lett. 121, 136805 (2018)
• S. C. Baek*, V. P. Amin*, Y-W Oh, G. Go, S-J. Lee, G-H. Lee, K-J. Kim, M. D. Stiles, B-G. Park & K-J. Lee, Spin currents and spin torques in ferromagnetic trilayers, Nature Materials, 17, 509–513 (2018)
• S. Klinger, V. P. Amin, S. Geprägs, K. Ganzhorn, H. Maier-Flaig, M. Althammer, H. Huebl, R. Gross, R. D. McMichael, M. D. Stiles, S. T. B. Goennenwein, and M. Weiler, Spin-Torque Excitation of Perpendicular Standing Spin Waves in Coupled YIG/Co Heterostructures, Phys. Rev. Lett. 120, 127201 (2018)
• V. P. Amin and M. D. Stiles, Spin transport at interfaces with spin-orbit coupling: Formalism, Phys. Rev. B 94, 104420 (2016)
• V. P. Amin and M. D. Stiles, Spin transport at interfaces with spin-orbit coupling: Phenomenology, Phys. Rev. B 94, 104419 (2016)
• Invited symposium: A new spin-orbit torque from interface-generated spin currents, MMM Meeting, Pittsburgh, PA, USA, November 11, 2017
• Invited symposium: Spin-orbit coupling at interfaces: blessing or curse for future spintronic devices? APS March Meeting, New Orleans, LA, USA, March 13, 2017