Colossal resistivity change associated with the charge ordered / disordered transition: Monte Carlo study

Abstract

Earlier theoretical approaches to manganites mainly stem from magnetic framework in which the electronic transports are thought to be spin-dependent and the double exchange plays a vital role. However, quite a number of experimental observations cannot be explained in the magnetic framework, yet. For example, multiplicate insulator-metal transitions and resistivity reduction induced by perturbations other than magnetic field, such as electric current, are not well understood in this framework. Here we present a comprehensive analysis on the magnetic framework and give a Monte Carlo study on the resistivity of a charge ordered/disordered model without accounting for the spin degree of freedom. The result shows a colossal resistivity change as a resultant of the transition between two types of insulated states. This transition has intrinsic difference from the popular insulated-to-metallic transition in the magnetic framework. The present scenario can be used to explain some experimental facts for electronic transports in manganites, which are not accessible in the magnetic framework.

Keywords

manganites, colossal magnetoresistance