Magnetoresistance of itinerant electrons interacting with local spins

[摘要] Transport properties of itinerant electrons interacting with local spins are analyzed as a function of the bandwidth, W, the exchange interaction, J, and the band filling, n, near the band edge. Numerical results have been obtained within the dynamical mean-field approximation and interpreted with the help of analytical treatments. If spatial correlations of the magnetic fluctuations can be neglected, and defining rho(m) as the magnetization dependent resistivity, we find that deltarho/rho(0)similar ton(-4/3) for J/W, nmuch less than1 (weak coupling, low density limit), deltarho/rho(0)similar toconst, for J/Wmuch greater than1, nmuch less than1 (double exchange, low density limit), where deltarho=partial derivativerho/partial derivativem(2)\(2)(m)-->0. Possible limitations from ignoring both localization effects and critical fluctuations are also considered.

[发布日期] 2004-11-01

[关键词] CHARGE-CARRIER DENSITY;DOUBLE-EXCHANGE;PHASE-SEPARATION;MODEL;SEMICONDUCTORS;PYROCHLORES;MANGANITES;DEPENDENCE;TRANSPORT;CRYSTALS