1 research outputs found
Chiral Decomposition of Twisted Graphene Multilayers with Arbitrary Stacking
We
formulate the chiral decomposition rules that govern the electronic
structure of a broad family of twisted N + M multilayer graphene configurations that combine arbitrary
stacking order and a mutual twist. We show that at the magic angle
in the chiral limit the low-energy bands of such systems are composed
of chiral pseudospin doublets that are energetically entangled with
two flat bands per valley induced by the moiré superlattice
potential. The analytic construction is supported by explicit numerical
calculations based on realistic parametrization. We further show that
vertical displacement fields can open energy gaps between the pseudospin
doublets and the two flat bands, such that the flat bands may carry
nonzero valley Chern numbers. These results provide guidelines for
the rational design of topological and correlated states in generic
twisted graphene multilayers