GLAM Special Seminar
Friday, December 7, 2018 at 4pm
McCullough Conference Room 335
Host: Prof. Shan X. Wang
Magnetic Memory with Topological Insulators and Ferrimagnetic Insulators
Department of Electrical and Computer Engineering
University of California, Los Angeles
Abstract: Ubiquitous smart devices and internet of things create tremendous data every day, shifting computing paradigm towards data-driven. Magnetic memory is one of the leading contenders for the embedded memory in the future computing paradigm. My research concerns innovating new types of magnetic memory to achieve ultrahigh energy efficiency, ultracompact size, and ultrafast speed from a perspective of material and heterostructure design. Improving energy efficiency of magnetic memory requires improving charge-to-spin conversion efficiency and reducing magnetic damping. We utilize topological insulators to achieve a conversion efficiency larger than one and integrate topological insulators into room temperature magnetic memories, which promises future ultralow power dissipation. We also investigate magnetic insulators as the potential information carriers, which could have much lower damping. To have a better scaling performance, we investigate skyrmions in magnetic thin films, which are arguably the smallest spin texture in nature. Especially, we have identified electronic signatures of room temperature skyrmions in magnetic insulators, which provide a new platform for exploring fundamental physics and pursuing practical applications. To have the highest operation speed, we explore compensated ferrimagnetic insulators, which could have THz dynamics due to the strong exchange coupling field. We realize energy efficient switching of the ferrimagnetic insulator in both ferromagnetic and antiferromagnetic states, promising electrical manipulation of ultrafast dynamics.
Biography: Qiming Shao is currently a Ph.D. candidate in the Department of Electrical and Computer Engineering at UCLA. He received his Bachler’s degree in 2013 from Tsinghua University and his Master’s degree in 2015 from UCLA. His main research interest is spintronic devices, and he has 23 publications in peer-reviewed journals and conferences, including Science, Nature Nanotechnology, Nature Materials, Nature Communications, Physical Review Letters, Nano Letters, and International Electron Device Meeting. He is a recipient of 2018-2019 UCLA Dissertation Year Fellowship, two Best Poster Awards at 2018 International Conference on Magnetism, 2015 Qualcomm Innovation Fellowship finalist, and 2012 Tsinghua-Changhong Scholarship for Comprehensive Excellence.