Recent Activities

李听昕:Integer and fractional quantum anomalous Hall effects in 2D semiconductor moiré superlattices

2023-10-20  

报告题目: Integer and fractional quantum anomalous Hall effects in 2D semiconductor moiré superlattices

报告人: 李听昕,上海交通大学

时间地点: 10月25日上午10:00,理科楼C302

摘要:

The emergence of topological moiré flat bands provides exciting opportunities to realize the lattice analogs of both the integer and fractional quantum Hall effects without the need for an external magnetic field. These effects are known as the integer and fractional quantum anomalous Hall (IQAH and FQAH) effects. In this talk, I will mainly present electrical transport studies of moiré superlattices built on 2D transition metal dichalcogenide (TMDc) semiconductors. We have successfully achieved highly tunable topological phases in both TMDc heterobilayer and TMDc homobilayer moiré superlattices. Specifically, we have observed a robust IQAH effect and signatures of quantum spin Hall effect in AB-stacked WSe2/MoTe2. In addition, both the IQAH effect and the long-sought FQAH effect have been realized in twisted bilayer MoTe2. Furthermore, the band topology in TMDc moiré superlattices is highly tunable by external electric fields, which enable us to realize novel topological quantum phase transitions. Our studies pave the path for discovery of a wealth of emergent phenomena arising from the interplay between strong correlations and topology in 2D moiré superlattices.

[1] F. Xu et al. PRX 13, 031037 (2023).

[2] T. Li et al. Nature 600, 641-646 (2021).

[3] T. Li et al. Nature 597, 350-354 (2021).

报告人简介: 李听昕,2011年于西北大学获学士学位,2016年于北京大学获博士学位。2016年至2021年先后在美国莱斯大学(2016.9-2018.3)和美国康奈尔大学(2018.3-2021.5)从事博士后研究,2021.6加入上海交通大学物理与天文学院,任长聘教轨副教授,博士生导师。从事实验凝聚态物理研究,主要研究兴趣为低维量子材料中的拓扑物理、强关联物理、磁性物理和超导物理等。近几年在二维半导体莫尔超晶格、二维拓扑绝缘体、二维磁性材料等方向取得了一系列研究成果,发表学术论文20余篇,其中包括第一作者/通讯作者 Nature 两篇、Nature 子刊四篇、PRX/PRL 三篇。