Quest for High Temperature and Functional Quantum Anomalous Hall State

Speaker: Lei Pan
Affiliation: UCLA Ph.D. Candidate


Dissipationless electron transport has been a holy grail in condensed matter physics. Two known physical approaches including the superconductivity and quantum Hall effect have been limited within research labs because of the requirement of low temperature or high external magnetic field, respectively. Quantum anomalous Hall effect (QAHE) is a new dissipationless electron transport mechanism discovered in magnetic topological insulators. QAHE can be viewed as the zero-field version of quantum Hall effect which can be a room temperature phenomenon. Just like quantum Hall effect, dissipationless chiral edge states will emerge at the sample boundary when right physical conditions are met. Since its discovery, such phenomenon in QAH insulator has attracted great interest in this field because of many potential application implications.

In this talk, the following topics will be covered: 1. Realization of quantum anomalous Hall effect in magnetic topological insulators; 2. Observation of metal-to-insulator transition in quantum anomalous Hall insulators; 3. Probing the low temperature limit of QAHE in current material systems; 4. Magnetic coupling and proximity effect in topological insulator-antiferromagnet heterostructure; and 5. Discovery of chiral Majorana fermions in quantum anomalous Hall insulator-superconductor heterostructures.


Lei Pan is currently a Ph.D. candidate in the Electrical and Computer Engineering Department of UCLA. He received his B.Eng (1st Class Honors) and M.Sc degree from Nanyang Technological University and UCLA in 2013 and 2015, respectively. He was awarded the Electrical Engineering Department fellowship in 2013 and was a finalist in Qualcomm innovation fellowship 2015. His Ph.D. research focused on molecular beam epitaxy growth of topological insulators and its related exotic physical properties. He is the author of more than 20 journal publications and has accumulated more than 800 citations. His co-first-authored paper on chiral Majorana fermions published in 2017 (Science 357,6348,294) is believed to be the first quantized evidence of this quasiparticle that may potentially be used in fault-tolerant quantum computers.  Lei was also a memory applications intern working on 3D-NAND testing and qualifications in Western Digital for the summer of 2018.

For more information, contact Prof. Kang L. Wang ()

Date(s) - Mar 19, 2019
2:00 pm - 4:00 pm

E-IV Faraday Room #67-124
420 Westwood Plaza - 6th Flr., Los Angeles CA 90095