Z. A. H. Goodwin, V. Vitale, X. Liang, A. A. Mostofi and J. Lischner, Hartree theory calculations of quasiparticle properties in twisted bilayer graphene, Electronic Structure 2, 034001 (2020)

Twisted bilayer graphene (tBLG) has generated a tremendous amount of interest in the condensed matter physics community (read our earlier research spotlights on the twist angle dependence of electron correlations in tBLG and the critical role of device geometry on the phase diagram of tBLG). Recent tunnelling experiments have found signatures corresponding to correlated insulator states as well as a number of other observations that cannot be understood within the framework of non-interacting electrons.

In a paper appearing in Physical Review B, we study the behaviour of interacting electrons in twisted bilayer graphene near the magic angle using atomistic Hartree theory. In particular, we calculate band structures and (local) densities of states in the metallic state as function of doping for a variety of twist angles. Our results explain several features of the experimentally observed tunnelling spectra. We also provide a simple parametrisation of the Hartree potential which enables Hartree band structures to be calculated without the need for self-consistency.

This work was part of Zachary Goodwin’s PhD in the Centre for Doctoral Training in Theory and Simulation of Materials. Zachary is supervised by Johannes Lischner and Arash Mostofi.