A Renormalization Group based framework to study twisted bilayer graphene
A Tribute to Giosi Benfatto, University of Roma Tre, Italy
September 18, 2025
The electronic properties of twisted bilayer graphene (TBG) has garnered much attention from the condensed matter community recently. TBG is obtained by stacking two graphene monolayers on top of each other, and rotating one of them with respect to the other. Theoretical and experimental analyses have found that the electronic properties of TBG depend very strongly on the angle between the layers. In fact, a handful of "magic" angles have been predicted at which TBG becomes a supercondutor, and this has even been verified experimentally.
The main model used to study TBG is an effective one, and was derived by Bistritzer and MacDonald. In this talk, I will present recent results on developing a framework to study TBG from first principles. To be more exact, we consider a tight-binding model for the electrons, but make no further approximations. Our approach is based on ideas by Giosi Benfatto and V. Mastropietro, and uses the renormalization group to study TBG in cases in which the twisting angle satisfies certain diophantine conditions.
This is joint work with V. Mastropietro.
Slides
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- tarball: 25benfattomem-1.0.tar.gz