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Anderson impurity in pseudo-gap Fermi systems

R. Bulla·Th. Pruschke·A. C. Hewson
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Abstract

We use the numerical renormalization group method to study an Anderson impurity in a conduction band with the density of states varying as rho(omega) \propto |omega|^r with r>0. We find two different fixed points: a local-moment fixed point with the impurity effectively decoupled from the band and a strong-coupling fixed point with a partially screened impurity spin. The specific heat and the spin-susceptibility show powerlaw behaviour with different exponents in strong-coupling and local-moment regime. We also calculate the impurity spectral function which diverges (vanishes) with |omega|^{-r} (|ω|^r) in the strong-coupling (local moment) regime.

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R. Bulla, Th. Pruschke, A. C. Hewson. 1997-07-01. Anderson impurity in pseudo-gap Fermi systems. https://doi.org/10.1088/0953-8984%2F9%2F47%2F014

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