Electronic Griffiths phase of the d=2 Mott transition
Abstract
We investigate the effects of disorder within the T=0 Brinkman-Rice (BR) scenario for the Mott metal-insulator transition (MIT) in two dimensions (2d). For sufficiently weak disorder the transition retains the Mott character, as signaled by the vanishing of the local quasiparticles (QP) weights Z_{i} and strong disorder screening at criticality. In contrast to the behavior in high dimensions, here the local spatial fluctuations of QP parameters are strongly enhanced in the critical regime, with a distribution function P(Z) ~ Z^{\alpha-1} and \alpha tends to zero at the transition. This behavior indicates a robust emergence of an electronic Griffiths phase preceding the MIT, in a fashion surprisingly reminiscent of the "Infinite Randomness Fixed Point" scenario for disordered quantum magnets.
Cite
@article{arxiv.0808.0913,
title = {Electronic Griffiths phase of the d=2 Mott transition},
author = {E. C. Andrade and E. Miranda and V. Dobrosavljevic},
journal= {arXiv preprint arXiv:0808.0913},
year = {2009}
}
Comments
4+ pages, 5 figures, final version to appear in Physical Review Letters