Sponsored by the Iowa State University Student Chapter of The Optical Society.
Speaker: Mo Li, Associate Professor of Electrical and Computer Engineering at University of Minnesota
Title: Coupling Spinning Photons with Spinning Electrons in Opto-Spintronic Devices
Abstract: Optoelectronic devices directly couple and convert photons and electrons for communication, computation and imaging. An emerging category of photonic devices, opto-spintronic devices, couples photons with the spin of the electron in various materials. They provide an efficient interface between optical communication and spintronics systems in the post-Moore era of computation and communications. In this talk, I will discuss the role of photon’s spin angular momentum in integrated photonics devices. I will show two types of devices that directly couples photon spins with electron spins. In the first device, we show that ultrafast optical pulses can switch the free layer in a magnetic tunnel junction in a sub-picosecond timescale. In the second device, we show that light in a waveguide with transverse spin angular momentum (SAM) can generate a directional, spin-polarized photocurrent in a topological insulator.
Bio: Mo Li is an Associate Professor in the Department of Electrical and Computer Engineering at the University of Minnesota, where he joined the faculty in 2010. From 2007 to 2010, he was a postdoctoral associate in the Department of Electrical Engineering at Yale University. He received his Ph.D. degree in Applied Physics from Caltech in 2007, B.S. degree in Physics from USTC in 2001. His distinctions include an NSF CAREER Award in 2014, McKnight Land-Grant Professorship in 2013 and AFOSR Young Investigator Award in 2012. His current research areas include nanophotonics, nano-optomechanical systems (NOMS), 2D material optoelectronics, opto-spintronics and quantum photonics.