Thursday, October 2, 2008, Condensed Matter Seminar, Dr. Chungwei Lin Dept. Columbia University, "Theory of Manganite Superlattices," 4:30 PM, 104 Thaw Hall, PITT

Abstract

A theoretical model is proposed for the (0,0,1) superlattice manganite system (LaMnO_3)_n(SrMnO_3)_m. The model includes the electron-electron, electron-phonon, and cooperative Jahn-Teller interactions. It is solved using a version of the single-site dynamical mean field approximation generalized to incorporate the cooperative Jahn-Teller effect. The phase diagram and conductivities are calculated. The behavior of the superlattice is found, to a good approximation, to be an average over the density-dependent properties of individual layers, with the density of each layer fixed by electrostatics.