Time: 10:00-11:30, July 2, 2025

时间：2025年7月2日（星期三）上午10:00-11:30

Host: Prof. Ruihua HE, PI of School of Science, Westlake University

主持人: 西湖大学物理系PI 何睿华

Venue: E10-211, Yungu Campus, Westlake University

地点:云谷校区E10-211教室

Lecture Language: Chinese

讲座语言: 中文

沈大伟教授

中国科学技术大学

主讲人/Speaker：

Prof. Dawei Shen received his B.S. and PhD. degrees in condensed matter physics from the Department of Physics of Fudan University in June 2003 and June 2008, respectively. From Dec. 2008 to Dec. 2011, he carried out post-doctoral work in Department of Physics of Cornell University. He was an associate professor (Jan. 2011~ Dec. 2015) and then a full professor (Jan. 2016 ~ Dec. 2022) at Shanghai Institute of Microsystem and Information Technology, CAS. In 2023, he moved to University of Science and Technology of China (USTC) and has been the full professor since then. His research focuses on the angle-resolved photoemission spectroscopy (ARPES) study of electronic structure of novel quantum materials. He also designed and then built the in-situ ARPES beamline BL-03U at SSRF. So far, he has been authored or co-authored more than 140 papers published in top peer-reviewed journals, e.g., Nature, Nature materials, Nature communications, PRL and PRX, which have been cited over 5600 times.

摘要/Abstract:

AM has been proposed as a third fundamental magnetic phase beyond traditional ferromagnetism and antiferromagnetism in crystals with collinear magnetic order. Electronic structure probing techniques like ARPES and SARPES can detect momentum-dependent band splitting and spin polarization induced by AM, considered the gold standard for identifying AM order in compounds. Employing high-resolved Micro-ARPES BL03U at SSRF, we performed a focused investigation of these materials, especially CrSb, and mapped its three-dimensional electronic structure. Due to accurate Brillouin zone positioning, our results on the (001) and (100) surfaces of CrSb consistently confirmed its AM characteristics. Notably, the band splitting near the Fermi level reached up to 1 eV, the highest value recorded among all confirmed AM materials to date. For the other workhorse material of RuO₂, we employed SARPES to investigate the band structure and spin polarization of both thin-film and single-crystal samples. Contrary to expectations of AM, our analysis indicates that RuO₂’s electronic structure aligns with those predicted under nonmagnetic conditions, exhibiting no evidence of the hypothesized spin splitting. Additionally, we observe significant in-plane spin polarization of the low-lying bulk bands, which contrasts with the d-wave spin texture due to time-reversal symmetry breaking in AM.

讲座联系人/Contact:

School of Science, Zeyuan LI, Email: lizeyuan@westlake.edu.cn