Monte Carlo study of the one-orbital model for manganites in the CMR regime

ORAL

Abstract

The thermal phase transition in the one-orbital model for manganites with cooperative phonons and superexchange coupling is studied using Monte Carlo simulations. In the absence of on-site disorder, the model has a second order phase transition from a paramagnetic insulating phase to a ferromagnetic metallic phase in the CMR regime. The CMR effect is found to be associated with short-range charge and spin correlations in the insulating phase. This clearly shows that the CMR effect arises from the competition between the ferromagnetic and a charge-ordered competing states. Motivated by a recent STM experiment, we also studied the local density of states in this one-orbital model. We show how the experimental results can be understood within our model.

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Authors

  • Rong Yu

    • Department of Physics and Astronomy, University of Tennessee and Materials Science and Technology Division, Oak Ridge National Laboratory
    • Department of Physics, University of Tennessee

  • Cengiz Sen

  • Gonzalo Alvarez

    • ORNL

  • Elbio Dagotto

    • Oak Ridge Natl. Lab. and Univ. Tennessee, TN, USA
    • Department of Physics and Astronomy, University of Tennessee and Materials Science and Technology Division, Oak Ridge National Laboratory
    • Department of Physics, University of Tennessee and Condensed Matter Sciences Division, ORNL