Strong correlations and topology in 2D semiconductor moiré superlattices

二維半導體莫爾超晶格中的強關聯和拓撲

報告人: 李聽昕 , 上海交通大學 物理與天文學院

時    間：2024年11月14日  15:00

地    點：沙河校區beat365英国官网网站C511

Abstract:

Two-dimensional (2D) semiconducting transition metal dichalcogenide (TMDc) moiré superlattices have emerged as a highly tunable platform for investigating novel quantum states of matter arising from strong electronic correlations and nontrivial band topology. We have successfully realized highly tunable topological flat bands in both TMDc heterobilayer and TMDc homobilayer moiré superlattices. Specifically, by performing low-temperature transport measurements, we have observed a robust integer quantum anomalous Hall (IQAH) effect and signatures of quantum spin Hall effect in WSe2/MoTe2 moiré heterostructures. Remarkably, both the IQAH effect and the long-sought fractional quantum anomalous Hall (FQAH) effect have been observed in twisted bilayer MoTe2. Moreover, ferromagnetism and Chern insulator states have also been observed in the second moiré band of twisted MoTe2. The band topology in TMDc moiré superlattices is highly tunable by external electric field and magnetic field, which enable us to realize novel topological quantum phase transitions. Our studies pave the path for the investigation of fractional phases of matter and anyonic statistics at zero magnetic field based on 2D moiré materials.

About the Speaker:

上海交通大學副教授，入選國家海外高層次人才引進計劃青年項目。
2011年在西北大學獲得物理學學士學位，2016年于北京大學beat365英国官网网站獲得博士學位，2016年至2021年先後在美國萊斯大學和美國康奈爾大學從事博士後研究，2021年6月加入上海交通大學物理與天文學院。近年來在二維半導體莫爾超晶格、石墨烯、分數量子反常霍爾效應實驗證明等研究方向取得了優秀的學術成果，發表期刊論文30餘篇，包括第一/通訊作者的 Nature 3篇、Nature 子刊 4篇、Physical Review X 2篇，Physical Review Letters 2篇。