Abstract: We create honeycomb superlattice structures in TMD moiré materials as model systems to
study magnetism, electronic correlations and topology. In twisted MoTe 2 , we realize topological flat
bands that closely resemble the lowest Landau level but in the absence of an external magnetic field.
We present evidence for integer and fractional Chern states [1], which are the lattice analogues of
integer and fractional quantum Hall states at zero magnetic field. We further explore correlated states in
twisted WSe 2 and demonstrate their tunability with twist angle, electric and magnetic fields [2]. By
relating these findings to the continuum model valence band structure, we provide an understanding for
our observations and offer guidance for designing homobilayer moiré materials.
References:
1. Zeng, Y. et al. Thermodynamic evidence of fractional Chern insulator in moiré MoTe 2 . Nature (2023).
https://doi.org/10.1038/s41586-023-06452-3
2. Knüppel, P. et al. Correlated states controlled by tunable van Hove singularity in moiré WSe2
(submitted, preprint at https://doi.org/10.48550/arXiv.2406.03315).
Bio: Patrick Knüppel pursued studies in physics and obtained his PhD degree at ETH
Zürich in Switzerland. His work focused on the intersection of strongly
correlated electrons and photonics, realized with gallium arsenide quantum
wells embedded in optical cavities. Currently, he is a Postdoctoral Fellow at
Cornell University in the Laboratory of Atomic and Solid State Physics. His
research explores condensed matter physics in moiré materials built from 2D
van der Waals materials.