Composite magnetoelectric technique, a universal ultrahigh sensitive method for correlated quantum materials

by Prof. Yisheng Chai (Chongqing University)

Monday 9 Jun 2025, 10:00 → 11:00 Asia/Shanghai

Tsung-Dao Lee Institute/N4F-N400 - meeting room (Tsung-Dao Lee Institute)

Time: 10:00 AM Jun 9 (Monday), 2025

Host: Prof. Haibiao Zhou

Venue: TDLI Meeting Room N400

Tencent meeting link:  https://meeting.tencent.com/dm/nGYieVsG5I1v   Meeting ID: 564532149, no password

 

Abstract:

Over years of dedicated research, we have established that the piezoelectric component in magnetoelectric composite materials can function effectively as a strain gauge. The voltage signal arising from magnetoelectric coupling offers a reliable means to determine the magnetostriction coefficient of materials. Building on this straightforward yet powerful concept, we developed a novel measurement technique by integrating a PMN-PT crystal as the strain sensor in a layered magnetoelectric composite structure. This technique is optimized for low-temperature and high-magnetic-field environments, enabling ultrahigh sensitivity across a wide range of quantum materials.

This presentation will focus on the following key advancements:

1. Development of a cryogenic and high-field measurement platform

2. High-resolution phase diagram mapping of magnetic materials

3. Comprehensive detection of quantum oscillations in half-metals

4. A novel criterion for identifying flux lattices in type-II superconductors

 

Biography:

Yisheng Chai is a Professor at the College of Physics, Chongqing University. He earned his B.Sc., M.Sc., and Ph.D. degrees from the Department of Physics at the University of Science and Technology of China (USTC), completing his Ph.D. in 2007. From 2004 to 2005, he was a visiting student at Risø National Laboratory in Denmark. He later conducted postdoctoral research at Seoul National University from 2007 to 2012. From 2012 to 2017, he served as an Associate Researcher at the Institute of Physics, Chinese Academy of Sciences (IOP, CAS). His research interests span single-phase and composite multiferroics, magnetoelectric coupling phenomena, superconductivity, and strongly correlated electron systems. He is also involved in developing advanced techniques for thermal transport and magnetic property measurements under extreme conditions. He has led or participated in several major research projects funded by the National Natural Science Foundation of China.