Fabian Eickhoff · Frithjof B. Anders

SciPost Physics · 2024

In this paper we consider a multi-band extension to the periodic Anderson model. We use a single site DMFT(NRG) in order to study the impact of the conduction band mediated effective hopping of the correlated electrons between the correlated orbitals onto the heavy Fermi-liquid formation. Whereas the hybridization of a single impurity model with two distinct conduction bands always adds up constructively, TK ∝ exp(−const U/(Γ1 + Γ2)), we show that this does not have to be the case in lattice models, where, in remarkable contrast, also an low-energy Fermi-liquid scale T0 ∝ exp(−const U/(Γ1−Γ2)) can emerge due to quantum interference effects in multi-band models, where U denotes the local
Coulomb matrix element of the correlated orbitals and Γi the local hybridization strength of band i. At high symmetry points, heavy Fermi-liquid formation is suppressed which is associated with a breakdown of the Kondo effect. This results in an asymptotically scale-invariant (i.e., power-law) spectrum of the correlated orbitals ∝ |ω|1/3, indicating non-Fermi liquid properties of the quantum critical point, and a small Fermi surface including only the light quasi-particles. This orbital selective Mott phase demonstrates the possibility of metallic local criticality within the general framework of ordinary single site DMFT.

SciPost Physics (2024)
https://doi.org/10.21468/SciPostPhys.17.3.069

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