Title: Spintronic devices in novel magnets
Speaker: Prof. Yu Ye, School of Physics, Peking University
Time&Location: 12:00 pm, May. 23, Room B501, Tangzhongying Building
Efficiently modulating spin configurations in magnets, especially by electrical means, is at the heart of spintronic devices. Novel magnets, such as 2D and topological magnets, couple topology, multiple degreesoffreedom, and magnetism, making them into promising materials for the high-efficiency spintronic devices previously impossible. In this talk, I will give two examples of new paradigms for constructing efficient spintronic devices using novel magnets.1) We report the efficient magnetism modulation in magnetic Weyl semimetal Co3Sn2S2 nanoflakes with perpendicular magnetic anisotropy by direct current injection. Through two independent methods, we reveal that the effective field of the current-induced spin-transfer torque reaches as high as 2.4-5.6 kOe MA−1 cm2, and the threshold current density for driving the magnetic domain wall is as low as <5.1×105 A cm−2 without an external field, and <1.6×105 A cm−2 with a moderate external field. 2) With a 2D stripy antiferromagnetic insulator CrOCl, we report the high-order nonlinear magnetoelectric coupling (MEC) effect. By measuring the tunneling resistance of CrOCl on the dependence of temperature, magnetic field, and applied voltage, we verified the MEC down to the 2D limit and unraveled its mechanism. Utilizing the multi-stable states in magnetic phase transition and MEC, we achieved multi-state data storage in the tunneling devices.
Yu Ye is an associate professor in the School of Physics at Peking University. He received his Ph.D. degree in condensed matter physics from Peking University in 2012. Prior to joining PKU in July 2016, Yu was working as a postdoctoral researcher at the University of California, Berkeley. His group (http://faculty.pku.edu.cn/yeyu) currently is interested in light-matter interactions and electrical transport properties in condensed matter physics, with an emphasis on novel physical phenomena emerging in atomically-thin materials, van der Waals heterostructures and surfaces/interfaces by nanoscale device designs, low-T-high-B optical spectroscopy, and electrical transport measurements. Yu published more than 100 research papers and earned >7500 citations with an h-index of 41.