Kondo breakdown in multi-orbital Anderson lattices induced by destructive hybridization interference

In this paper we consider a multi band extension to the periodic Andersonmodel. We use a single site DMFT(NRG) in order to study the impact of theconduction band mediated effective hopping of the correlated electrons betweenthe correlated orbitals onto the heavy Fermi liquid formation. Whereas thehybridization of a single impurity model with two distinct conduction bandsalways adds up constructively, $T_{K}\propto \exp(-\alphaU/(\Gamma_1+\Gamma_2))$, we show that this does not have to be the case inlattice models, where, in remarkable contrast, also an emerging low-energyFermi liquid scale $T_0\propto \exp(-\alpha U/(\Gamma_1-\Gamma_2))$ is possibledue to quantum interference effects in multi band models. At high symmetrypoints, heavy Fermi liquid formation is suppressed which is associated with abreakdown of the Kondo effect. This results in an asymptoticallyscale-invariant (i.e., power-law) spectrum of the correlated orbitals$\propto|\omega|^{1/3}$ and a small Fermi surface including only the lightquasi-particles. This orbital selective Mott phase demonstrates the possibilityof metallic local criticality within the general framework of ordinary singlesite DMFT.