Quantum Anomalous Hall Effect and New Progress

22 Mar 2019 - 3:30pm
Martin Wood Lecture Theatre

Quantum Anomalous Hall Effect and New Progress
Professor Qi-Kun Xue
Tsinghua University & Beijing Academy of Quantum Information Sciences, Beijing 100084, China

The quantum anomalous Hall (QAH) effect is a quantum Hall effect induced by spontaneous magnetization, and occurs in two-dimensional insulators with topologically nontrivial electronic band structure which is characterized by a non-zero Chern number. It was first experimentally observed in the thin films of magnetically doped (Bi,Sb)2Te3 topological insulators (TIs) in 2013, more than thirty years after the discovery of the first quantum Hall effect by Klaus von Klitzing. In this talk, I will report on some recent experimental progresses in this direction. By co-doping of Cr and V into (Bi,Sb)2Te3 TI films, we are able to significantly increase the observation temperature of QAH effect. More interestingly, we can construct other topological states of matter such as axion insulator, quantum spin Hall insulator and QAH insulator of high Chern number by growing QAH insulator-based heterostructures.

About the speaker: Qi-Kun Xue, received his BSc in Shan-Dong University in 1984, and PhD degree in condensed matter physics from Institute of Physics, the Chinese Academy of Sciences (CAS) in 1994. From 1994 to 2000, he worked as a Research Associate at IMR, Tohoku University, Japan and a visiting Assistant Professor at Department of Physics, North Carolina State University, USA. He became a Professor at Institute of Physics, CAS in 1999. He was elected into The Chinese Academy of Sciences in 2005. Since 2005, he has been a Professor in Department of Physics, Tsinghua University.

From 2010 to 2013, he was the Chair of Department of Physics and the Dean of School of Sciences. He became the Vice President for Research of Tsinghua University in May 2013 and the Director of Beijing Academy of Quantum Information Sciences in December 2017. He won the Future Science Prize for Physical Science in 2016 and the TWAS Prize in Physics in 2010. His research interests include scanning tunneling microcopy/spectroscopy, molecular beam epitaxy, low-dimensional and interface-related superconductivity, topological insulators, and quantum size effects in various low-dimensional structures. He has authored/coauthored ~400 papers with a citation of ~16000 times. He has presented more than 150 invited/keynote/plenary talks at international meetings/conferences, such as American Physical Society March Meeting (1996, 2005, 2010, 2012, 2014). Currently, he is the Fellow of American Physical Society, the Associate Editor of National Science Review, the Editors-in-Chief of Surface Review & Letters, and on the Editorial Board of Physical Review B, Applied Physics Letters, Journal of Applied Physics, Surface Science Reports and AIP Advance.
Followed by tea/coffee in the Clarendon Laboratory Common Room

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