Quantum critical point with competing propagating and diffusive spin excitations
arXiv:cond-mat/9810041
Abstract
Feedback effects due to spin fluctuation induced precursors in the fermionic quasiparticle spectrum are taken into account in the description of a quantum critical point of itinerant spin systems. A correlation length dependent spin damping occurs, leading to a dynamical scaling with z\approx 1 which non-trivially competes with the conventional spin wave behavior. We obtain, within a one loop renormalization group approach, a quantitative explanation for the scaling behavior seen in underdoped cuprate superconductors.
4 pages, 4 figures