Description:

Recent progress in two-dimensional materials has made the fabrication of artificial two-dimensional crystals – moiré materials [1-3] - with lattice constants on the 10 nm scale routine.  The significance of the large lattice constants is that it allows the number of electrons per effective atom in these crystals to be varied by around ten using electrical gates – making it possible to move continuously across that many rows of the artificial material’s periodic table.   Over the past decade, moiré materials have been established as a rich platform for fundamental many-electron physics studies – realizing almost all phenomena known from decades of study of atomic-scale crystals and also new phenomena related to strong correlations in materials with topologically non-trivial energy bands.  My talk will survey the moiré-materials field with a focus on recent work related to the fractional quantum anomalous Hall effect in MoTe2 homobilayer moiré materials.  

[1] R. Bistritzer, and A.H. MacDonald, Proceedings of the National Academy of Sciences 26, 12233 (2011). 
[2] F. Wu, T. Lovorn, E. Tutuc, and A.H. MacDonald, Phys. Rev. Lett. 121, 026402 (2018).
[3] F. Wu, T. Lovorn, E. Tutuc, I. Martin, and A.H. MacDonald, Phys. Rev. Lett. 122, 086402 (2019).  

Allan MacDonald, Professor, University of Texas - Austin

Host: Anupam Garg