Role of Complex Energy Landscapes and Strains in Multiscale Inhomogeneities in Perovskite Manganites

We analyze the essential role played by complex energy landscapes in the nanometer- to micron-scale inhomogeneities observed in perovskite manganites using a model expressed in terms of symmetrized atomic-scale lattice distortion modes. We also examine the stability of large metal and insulator domains in the absence of defects. Our results demonstrate that an intrinsic mechanism, which involves long-range interactions between strain fields, the Peierls-Nabarro energy barrier, and complex energy landscapes with multiple metastable states, rather than an extrinsic mechanism such as chemical randomness, is responsible for the inhomogeneity in perovskite manganites.