Critical Local-Moment Fluctuations, Anomalous Exponents, andω/TScaling in the Kondo Problem with a Pseudogap

Kevin Ingersent, Qimiao Si
2002 Physical Review Letters  
Experiments in heavy-fermion metals and related theoretical work suggest that critical local-moment fluctuations can play an important role near a zero-temperature phase transition. We study such fluctuations at the quantum critical point of a Kondo impurity model in which the density of band states vanishes as |E|^r at the Fermi energy (E = 0). The local spin response is described by a set of critical exponents that vary continuously with r. For 0 < r < 1, the dynamical susceptibility exhibits
more » ... eptibility exhibits omega/T scaling with a fractional exponent, implying that the critical point is interacting.
doi:10.1103/physrevlett.89.076403 pmid:12190538 fatcat:635kpjk4mbebjo6jeojusd4ane