Upper critical dimension in a quantum impurity model: Critical theory of the asymmetric pseudogap Kondo problem
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Contributors
Abstract
Impurity moments coupled to fermions with a pseudogap density of states display a quantum phase transition between a screened and a free moment phase upon variation of the Kondo coupling. We describe the universal theory of this transition for the experimentally relevant case of particle-hole asymmetry. The theory takes the form of a crossing between effective singlet and doublet levels, interacting with low-energy fermions. Depending on the pseudogap exponent, this interaction is either relevant or irrelevant under renormalization group transformations, establishing the existence of an upper-critical "dimension" in this impurity problem. Using perturbative renormalization group techniques we compute various critical properties and compare with numerical results.
Details
Original language | English |
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Article number | 094502 |
Pages (from-to) | 094502-1-094502-4 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 70 |
Issue number | 9 |
Publication status | Published - Sept 2004 |
Peer-reviewed | Yes |
Externally published | Yes |