【直播】【南科大】香港科技大学Junwei Liu 教授 学术报告

报告题目：

Giant piezomagnetism and noncollinear spin current from C-paired spin valley locking

报告时间：

2022年12月13日 14:30

报告嘉宾：

Junwei Liu（香港科技大学）

主办单位：

南方科技大学物理系

直播通道

蔻享学术直播间 识别二维码，即可观看直播。

报告人介绍

Junwei Liu
香港科技大学

Prof. Junwei Liu obtained his PhD in the department of physics, Tsinghua University, in 2014, and then he started his postdoctoral research in Massachusetts Institute of Technology. He joined Hong Kong University of Science and Technology in 2017 as an assistant professor.Currently, his research focuses on two parts: 1) explore new phase of quantum matter including both symmetry-breaking phases and topological phases, and their novel properties, material realizations, experimental signatures and potential applications; 2) combination of advanced machine learning techniques and quantum physics, especially the combination of machine learning techniques and quantum Monte Carlo simulations and all optical neural networks. He has published more than 50 papers including 2 in Science and 1 in Nature, . He was awarded National Natural Science Foundation of China Excellent Young Scientist (Hong Kong and Macau) in 2020. 

报告简介

In this talk, I will take our recently proposed new type of spin-valley locking (SVL), named C-paired SVL, in antiferromagnetic systems. It directly connects the spin/valley space with the real space, and hence enables both static and dynamical controls of spin and valley to realize a multifunctional antiferromagnetic material. The new emergent quantum degree of freedom in the C-paired SVL is comprised of spin-polarized valleys related by a crystal symmetry instead of the time-reversal symmetry. Thus, both spin and valley can be accessed by simply breaking the corresponding crystal symmetry. Typically, one can use a strain field to induce a large net valley polarization/magnetization and use a charge current to generate a large noncollinear spin current. We predict the realization of the C-paired SVL in monolayer V₂Se₂O, which indeed exhibits giant piezomagnetism and can generate a large transverse spin current. Based on symmetry analysis and first-principles calculations, we also found C-paired SVL can exist in the following experimentally verified AFM materials, NaOsO₃, LaMnO₃, LaCrO₃, TbFeO₃, MnTe, RuO₂, MnF₂, FeF₂, CoF₂, and NiF₂. Our findings provide new opportunities to integrate various controls of spin and valley with nonvolatile information storage in a single material, which is highly desirable for versatile fundamental research and device applications.

---

推荐阅读

编辑：黄琦

蔻享学术 平台介绍

蔻享学术平台，国内领先的一站式科学资源共享平台，依托国内外一流科研院所、高等院校和企业的科研力量，聚焦前沿科学，以优化科研创新环境、传播和服务科学、促进学科交叉融合为宗旨，打造优质学术资源的共享数据平台。

识别二维码，

下载 蔻享APP  查看最新资源数据。

点击阅读原文，查看更多精彩报告！