10:30 am MCP 201
Origin of flat bands in Twisted Bilayer Graphene, Grigory Tarnopolsky, Harvard University
Several years ago, in a continuum model of the Twisted Bilayer Graphene, a dramatic flattening of electronic low energy bands was observed numerically at a magic angle of 1.1 degrees. This theoretical discovery is believed to provide a foundation for the various interacting phenomena which were recently observed experimentally near this magic angle, including unconventional superconductivity and correlated insulators.
In this talk I will present a variant of the continuum model where the bands are exactly flat at a series of magic angles, the biggest of which is 1.1 degrees. I will exhibit an analytic derivation of this and show that the wave functions of the exactly flat band are reminiscent of the Lowest Landau Level ones. I will also discuss application of this for a construction of the Laughlin wave function in Twisted Bilayer Graphene.