Integer and fractional quantum anomalous Hall effects in 2D semiconductor moiré superlattices
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TDLI Meeting Room N600 (East Wing of Floor 6, North Building)
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. Furthermore, both the IQAH effect and the long-sought FQAH effect have been realized in twisted bilayer MoTe2. 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 the investigation of fractionally charged excitations and anyonic statistics at zero magnetic field based on 2D moiré materials.
[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).
Dr. Tingxin Li received his Bachelor's degree in 2011 from Northwest University and Ph.D. degree in 2016 from Peking University. From 2016 to 2021, he conducted postdoctoral research at Rice University (2016.9-2018.3) and Cornell University (2018.3-2021.5). In June 2021, he joined the School of Physics and Astronomy at Shanghai Jiao Tong University as a tenure-track associate professor. His research focuses on topological physics, strong correlation physics, magnetism, and superconductivity in low-dimensional quantum materials. He has published over 20 academic papers, including two in Nature, four in Nature sub-journals, and three in PRX/PRL, as the first author or corresponding author.
Tencent meeting link: https://meeting.tencent.com/dm/HzgzzXtsHjr2 Meeting ID: 561 505 329
