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Integer and Fractional Chern insulators in moiré MoTe2
Speaker Dr. Yihang Zeng, Cornell University
Date 19 March 2024 (Tuesday)
Time 10:30 - 12:00
Venue Zoom (online)

The fractional Chern insulator (FCI), a lattice analogue of the renowned fractional quantum Hall state, was theorized to exist without external magnetic field. FCI provides a pathway towards novel topologically ordered quantum phases that are useful for decoherence-free quantum computation. Two-dimensional (2D) moiré materials, featuring strong correlation, non-trivial band topology and unparalleled tunability, stands as an ideal platform for realizing FCI. In this talk, I will first present our innovative optoelectronic detection method, which is capable of detecting the chemical potential in arbitrary 2D materials. Employing this new technique, we successfully observed an FCI and integer Chern insulator in the zero magnetic field limit in MoTe2-based moiré materials. In conclusion, I will discuss the future directions in my proposed research program.

Yihang Zeng received his bachelor’s degree from Peking University in China in 2015. He then joined Columbia University for his Ph.D. studies. Under the guidance of Professor Cory Dean, he studied graphene-based systems in the quantum Hall regime, through electrical transport measurements. After obtaining his Ph.D. in 2021, he became a postdoctoral researcher in the joint group of Kin Fai Mak and Jie Shan at Cornell University. His research there focuses on investigating the electronic properties in 2D moiré materials using optical sensing techniques. He co-invented a new optoelectronic method for probing the chemical potential in 2D devices. Employing this method, he made the first experimental observation of the fractional Chen insulator at zero magnetic field.

To request for Zoom information, please write to phweb@ust.hk.