Colossal resistivity change besides magnetoresistance: an extended theoretical framework for electronic transport of manganites

TL;DR

This paper proposes an extended theoretical framework for manganite electronic transport, emphasizing charge contributions to explain colossal resistivity changes beyond traditional magnetic-based models.

Contribution

It introduces a new framework that highlights the role of charge degrees of freedom and extrinsic factors in resistivity changes, expanding beyond existing magnetic-centric theories.

Findings

Identifies two origins of resistivity change: magnetic field-induced and extrinsic perturbations.

Highlights the significance of insulated-to-insulated transitions in resistivity.

Proposes a comprehensive model incorporating charge contributions for better explanation of experimental observations.

Abstract

Current theoretical approaches to manganites mainly stem from magnetic framework, in which the electronic transport is thought to be spin-dependent and the double exchange mechanism plays a core role. However, quite a number of experimental observations can yet not be reasonably explained. For example, multiplicate insulator-metal transitions and resistivity reduction induced by perturbations other than magnetic field, such as electric current, are not well understood. A comprehensive analysis on earlier extensive studies is performed and two types of origins for resistivity change are highlighted. Besides the insulated-to-metallic transition induced by external field such as magnetic field, the insulated-to-insulated transition induced extrinsically is even a more important source for the colossal resistivity change. We propose an extended framework for the electronic transport of manganites, in which the contribution of charge degree of freedom is given a special priority.