Observation of fractional quantum anomalous Hall effect
ORAL · Invited
Abstract
The synergy of topology, strong correlations, and spontaneous symmetry breaking can give rise to exotic quantum states of matter. A celebrated example is the rationally designed flat Chern band, which hosts fractional Chern insulators. These insulators can exhibit the fractional quantum anomalous Hall effect(FQAHE), which is the lattice analog of the fractional quantum Hall effect at zero magnetic field without Landau level formation. In this talk, I will present the experimental observation of high-temperature FQAHE in twisted MoTe2 bilayer, using combined magneto-optical spectroscopy and transport measurements. Additionally, I will present an anomalous Hall state around the filling factor of -1/2, the leading candidate for which is a composite Fermi liquid state. Notably, the states associated with the FQAH and associated effects can be electrically tuned into a variety of topologically trivial phases. These results mark a promising direction for the investigation of charge fractionalization and anyon statistics at zero magnetic field and elevated temperature.
*Measurements of the FQAH states are supported by DoE BES under award DE-SC0018171. Measurements of the integer QAH state are supported by the AFOSR FA9550-21-1-0177. Device fabrication and electrical transport measurements are partially supported by the Center on Programmable Quantum Materials, an Energy Frontier Research Center funded by DOE BES, under award DE-SC0019443. The understanding of magnetism and the topological phase diagram is partially supported by AFOSR Multidisciplinary University Research Initiative (MURI) programme, grant no. FA9550-19-1-0390. We also acknowledge the use of the facilities and instrumentation supported by the NSF MRSEC DMR-1719797.This research acknowledges the use of the millikelvin optoelectronic quantum material laboratory supported by the M. J. Murdock Charitable Trust.
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Publication:Cai, J., Anderson, E., Wang, C. et al. Signatures of fractional quantum anomalous Hall states in twisted MoTe2. Park, H., Cai, J., Anderson, E. et al. Observation of fractionally quantized anomalous Hall effect. Nature 622, 74–79 (2023). Eric Anderson et al. ,Programming correlated magnetic states with gate-controlled moiré geometry.Science381,325-330(2023).
Presenters
Jiaqi Cai
University of Washington
Authors
Jiaqi Cai
University of Washington
Eric Anderson
University of Washington at Seattle
University of Washington
Heonjoon Park
University of Washington
Yinong Zhang
University of Washington
Jiayi Zhu
University of Washington
Xiaoyu Liu
Univ of Washington
Chong Wang
University of Washington
William G Holtzmann
University of Washington
Chaowei Hu
University of Washington, Seattle
University of Washington
Zhaoyu Liu
University of Washington
Takashi Taniguchi
Kyoto Univ
National Institute for Materials Science
Research Center for Materials Nanoarchitectonics
Research Center for Materials Nanoarchitectonics, National Institute for Materials Science
National Institute for Materials Sciences
NIMS
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
National Institute for Material Science
International Center for Materials Nanoarchitectonics, NIMS, Japan
International Center for Materials Nanoarchitectonics, Tsukuba
National Institue for Materials Science
Kyoto University
National Institute of Materials Science
International Center for Materials Nanoarchitectonics and National Institute for Materials Science
Kenji Watanabe
National Institute for Materials Science
NIMS
Research Center for Electronic and Optical Materials, National Institute for Materials Science
Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
National Institute for Material Science
Jiun-Haw Chu
University of Washington
Department of Physics, University of Washington, Seattle, WA 98105
