Speaker
Description
Among the variety of correlated states exhibited by twisted bilayer graphene (TBG), the cascades in the spectroscopic properties and in the compressibility happen in a larger energy, twist angle and temperature range in comparison to other effects, pointing to a hierarchy of phenomena. Using Dynamical Mean Field Theory + Hartree calculations, we show that the spectral weight reorganization associated to the formation of local moments and heavy quasiparticles, and not a symmetry breaking process, is responsible for the cascade phenomena. Due to the fragile topology of TBG, a strong momentum differentiation is found in the incoherent spectral weight. The phenomena reproduced here include the cascade flow of spectral weight, the oscillations of the remote band energies and the asymmetric jumps of the inverse compressibility.
