Eur. Phys. J. B 9, 373-376 (1999)
https://doi.org/10.1007/s100510050779

Localization and dephasing driven by magnetic fluctuations in low carrier density colossal magnetoresistance materials

¹ Jack and Pearl Resnick Institute of Advanced Technology, Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel
² Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE, UK
³ Department of Electrical and Computer Engineering, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel

Received: 17 January 1999
Revised: 12 March 1999
Published online: 15 June 1999

Abstract

Localization and dephasing of conduction electrons in a low carrier density ferromagnet due to scattering on magnetic fluctuations is considered. We claim the existence of the "mobility edge" , which separates the states with fast diffusion and the states with slow diffusion; the latter is determined by the dephasing time. When the "mobility edge" crosses the Fermi energy a large and sharp change of conductivity is observed. The theory provides an explanation for the observed temperature dependence of conductivity in ferromagnetic semiconductors and manganite pyrochlores.