Abstract:

    Moiré superlattices formed in van der Waals materials have emerged as a new platform to explore strong correlation physics and topological physics in two-dimensional (2D) electronic systems. In this talk, I will mainly present electronic transport and compressibility studies of moiré superlattices built on 2D transition metal dichalcogenide (TMDc) semiconductors. A series of correlation-driven states, including Mott insulators [1], generalized Wigner crystals [2], and stripe phases [3], formed at either integer or fractional filling factors of the moiré superlattices. Benefiting from the extraordinary tunability of the system, an interaction-driven Mott transition has been realized experimentally [4]. Furthermore, we found the band topology also plays an important role in TMDc moiré superlattices, which enable us to realize a quantum anomalous Hall state in TMDc moiré superlattices [5]. Our studies pave the path for discovery of a wealth of emergent phenomena arising from the combined influence of strong correlation and topology in TMDc moiré superlattices.
[1] Y. Tang et al. Nature 579, 353-358 (2020).
[2] T. Li et al. Nature Nanotechnology (2021).
[3] C. Jin et al. Nature Materials 20, 940-944 (2021).
[4] T. Li et al. Nature (in-press).
[5] T. Li et al. arXiv:2107.01796