Giant Hall effect in nonmagnetic granular metal films

Phys Rev Lett. 2001 Jun 11;86(24):5562-5. doi: 10.1103/PhysRevLett.86.5562.

Abstract

Nearly 3 orders of magnitude enhancement in the Hall coefficient is observed in Cu(x)-(SiO(2))(1--x) granular films. This large enhancement of the Hall coefficient not only is significantly larger than the prediction of the classical percolation theory, but also occurs at a metal concentration identified to be the quantum percolation threshold. Measurements of the electron dephasing length and magnetoresistance, plus the TEM characterization of microstructures, yield a physical picture consistent with the mechanism of the local quantum interference effect.