Ambipolar gate effect and low temperature magnetoresistance of ultrathin La0.8Ca0.2MnO3 Films

TL;DR

This study investigates how electric fields influence resistance and magnetoresistance in ultrathin La0.8Ca0.2MnO3 films at low temperatures, revealing ambipolar effects linked to a pseudogap and charge-strain coupling.

Contribution

It demonstrates the large ambipolar gate effect and low temperature magnetoresistance in ultrathin manganite films, providing a unified interpretation based on pseudogap development and charge-strain interactions.

Findings

Large ambipolar decrease in resistance at low temperatures

Gate effect and magnetoresistance explained by pseudogap and charge-strain coupling

Implications for two-dimensional manganite behavior discussed

Abstract

Ultrathin La0.8Ca0.2MnO3 films have been measured in a field-effect geometry. The electric field due to the gate produces a large ambipolar decrease in resistance at low temperatures. This is attributed to the development of a pseudogap in the density of states and the couple of localized charge to strain. The gate effect and mangetoresistance are interpreted in a consistent framework. The implications for the low temperature behavior of a manganite film in the two dimensional limit are discussed.