Nanoscale Phase Separation in Colossal Magnetoresistance Materials: A Lesson for the Cuprates?

TL;DR

This paper reviews nanoscale phase separation in manganites and explores its implications for high-temperature cuprate superconductors, suggesting that similar phase competition and inhomogeneities could be fundamental to understanding their properties.

Contribution

It draws parallels between manganites and cuprates, proposing theoretical speculations on phase competition and inhomogeneities in high-temperature superconductors based on manganite insights.

Findings

Intrinsic inhomogeneities observed in cuprates resemble manganite phase separation.

The pseudogap temperature T* may be a Griffiths temperature for cluster formation.

Quenched disorder could be more influential in cuprates than previously thought.

Abstract

A recent vast experimental and theoretical effort in manganites has shown that the colossal magnetoresistance effect can be understood based on the competition of charge-ordered and ferromagnetic phases. The general aspects of the theoretical description appear to be valid for any compound with intrinsic phase competition. In high temperature superconductors, recent experiments have shown the existence of intrinsic inhomogeneities in many materials, revealing a phenomenology quite similar to that of manganese oxides. Here, the results for manganites are briefly reviewed with emphasis on the general aspects. In addition, theoretical speculations are formulated in the context of Cu-oxides by mere analogy with manganites. This includes a tentative explanation of the spin-glass regime as a mixture of antiferromagnetic and superconducting islands, the rationalization of the pseudogap temperature T* as a Griffiths temperature where clusters start forming upon cooling, the prediction of "colossal" effects in cuprates, and the observation that quenched disorder may be far more relevant in Cu-oxides than previously anticipated.