Europhys. Lett., 61 (6) , pp. 810-816 (2003)
Spectral scaling and quantum critical behaviour in the pseudogap Anderson modelM. T. Glossop and D. E. Logan
Oxford University, Physical and Theoretical Chemistry Laboratory South Parks Road, Oxford OX1 3QZ, UK
(Received 4 November 2002; accepted in final form 14 January 2003)
The pseudogap Anderson impurity model provides a classic example of an essentially local quantum phase transition. Here we study its single-particle dynamics in the vicinity of the symmetric quantum critical point (QCP) separating generalized Fermi-liquid and local-moment phases, via the local-moment approach. Both phases are shown to be characterized by a low-energy scale that vanishes at the QCP; and the universal scaling spectra, on all energy scales, are obtained analytically. The spectrum precisely at the QCP is also obtained; its form showing clearly the non-Fermi-liquid, interacting nature of the fixed point.
71.27.+a - Strongly correlated electron systems; heavy fermions.
75.20.Hr - Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions.
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