Giant Cluster Coexistence in Doped Manganites and Other Compounds

TLDR

Computational studies of manganese oxide models reveal large coexisting metallic and insulating clusters with equal electronic density, matching micrometer‑sized inhomogeneities observed in manganites and suggesting natural percolative behavior. The clusters arise from disorder in exchange and hopping amplitudes near first‑order transitions of the strongly coupled system, as illustrated qualitatively by a random‑field Ising model. These findings are general and extend to a variety of related compounds.

Abstract

Computational studies of models for manganese oxides show the generation of large coexisting metallic and insulating clusters with equal electronic density, in agreement with the recently discovered micrometer-sized inhomogeneities in manganites. The clusters are induced by disorder on exchange and hopping amplitudes near first-order transitions of the nondisordered strongly coupled system. The random-field Ising model illustrates the qualitative aspects of our results. Percolative characteristics are natural in this context. The conclusions are general and apply to a variety of compounds.