一、报告题目

Probing the Magnetic Structure of Atomically Thin Chromium Trihalide Using Magnetic Tunnel Junctions

二、报告人

蔡星汉 上海交通大学

三、报告时间

1月8日15：30

四、报告地点

中心校区知新楼C座1111房间

五、邀请人

陈延学 王以林

六、报告摘要

Recent discoveries of intrinsic layered ferromagnetism in insulating van der Waals crystals chromium trihalide (CrX3, X = Cl, Br or I) has created unprecedented opportunities for studying fundamental 2D magnetism and realizing novel functional devices. In this talk, I will discuss the magnetic structure of CrI3 and CrCl3 in the 2D limit by investigating the electron tunneling through their atomically thin flakes. I will demonstrate the intralayer ferromagnetic ordering and the layer-by-layer antiferromagnetic coupling in both CrI3 and CrCl3. The tunneling magnetoresistance (TMR) in CrI3 based magnetic tunnel junction is drastically enhanced with increasing CrI3 layer thickness owing to the spin-filtering effect, reaching a record of 19,000% for magnetic multilayer structures at low temperature. For atomically thin CrCl3, the weak magnetic anisotropy with an easy plane perpendicular to the c-axis is determined and its magnetic phase diagram is further constructed. This work offers a unique platform and a new means to explore the 2D ferromagnetism and engineer vdW spintronic devices.

七、报告人简介

蔡星汉，2015年于美国马里兰大学物理系获得博士学位，其后进入华盛顿大学物理系任研究助理，于2018年起担任上海交通大学电子信息与电气工程学院副教授，博士生导师，数次入选国家及省部级人才计划。其主要从事低维量子体系磁电与光电特性及相关器件的研究，曾多次在Science、Nature Nanotechnology、Nature Physics等权威期刊发表论文，并担任Nature Communications等知名杂志的审稿人。