Phase Separation Induced by Orbital Degrees of Freedom in Models for Manganites with Jahn-Teller Phonons

Abstract

The two-orbital Kondo model with classical Jahn-Teller phonons is studied using Monte Carlo techniques. The observed phase diagram is rich, and includes a novel regime of phase separation induced by the orbital degrees of freedom. Experimental consequences of our results are discussed. In addition, the optical conductivity $σ(ω)$ of the model is presented. It is shown to have several similarities with experimental measurements for manganites.

Accepted for publication in Phys. Rev. Letters, revised version of the paper, 5 pages, Revtex, with 4 figures embedded