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.
@article{arxiv.cond-mat/9810041,
title = {Quantum critical point with competing propagating and diffusive spin excitations},
author = {Joerg Schmalian},
journal= {arXiv preprint arXiv:cond-mat/9810041},
year = {2007}
}