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Critical theories for the pseudogap Kondo problem

Lars Fritz·Marijana Kircan·Matthias Vojta
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Abstract

We discuss quantum phase transitions in the pseudogap Kondo problem, which describes a magnetic moment coupled to conduction electrons with a power-law density of states, rho(omega) ~ |omega|^r. We show that different perturbative expansions, together with renormalization group techniques, provide effective low-energy field theories for the relevant critical fixed points. In particular, we review expansions near the lower-critical and upper-critical dimensions of the problem, being r=0 and r=1, respectively.

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Lars Fritz, Marijana Kircan, Matthias Vojta. 2004-06-14. Critical theories for the pseudogap Kondo problem. https://doi.org/10.1016/j.physb.2004.12.062

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