Activities

  1. universal principles of moire band structures

Jinhong Park

University of Cologne, Germany

30 August 2022 Tue 4 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

Moiré materials provide a highly tunable platform for engineering band structures that possibly facilitate the emergence of exotic correlated phases. In this talk, I am going to show that statistical principles can be used for explaining universal physical properties of the moiré materials. Our approach builds on three conceptual elements in momentum space: moiré lattice periodicity that defines a lattice in momentum space, quantum chaos induced by the hopping between the lattice sites, and Anderson localization by the effective disorder arising from the dispersion of unperturbed 2d layers. On the interplay between the elements, we define three different localization regimes in which generic moiré bands show different characteristics for their flatness and the spectral statistics. We further identify structures outside the statistical context, notably almost flat bands close to the extrema of the unperturbed spectra, and the celebrated ‘magic angle’ flat bands.