Orbital ordering in undoped manganites using Jahn-Teller interaction

Sudhakar Yarlagadda; Manidipa Mitra

paper

Orbital ordering in undoped manganites using Jahn-Teller interaction

arXiv:cond-mat/0310350

Abstract

To understand the orbital ordering of $L a M n O_{3}$ in the ground state, we study it in the A-type spin antiferromagnetic state. We calculate the two-dimensional response functions associated with the Jahn-Teller $Q_{2}$ and $Q_{3}$ distortions and find that they diverge at the wavevector $π$ , $π$ ). Furthermore, the $Q_{2}$ response function diverges faster which indicates that perhaps the ordering of the orbitals at low temperatures is dominated by the $Q_{2}$ distortion. We calculate the ground state energy for the cases when only one of the $Q_{2}$ and $Q_{3}$ modes is excited cooperatively and find that the $Q_{2}$ excited state yields lower energy.

Presented at Condensed Matter Days conference, Jadavpur Univ., Calcutta