Orbital Dzyaloshinskii-Moriya Exchange Interaction
Abstract
Superexchange calculation is performed for multi-orbital band models with broken inversion symmetry. Orbital-changing hopping terms allowed by the symmetry breaking electric field lead to a new kind of orbital exchange term closely resembling the Dzyaloshinskii-Moriya spin exchange. The final superexchange Hamiltonian in two dimensions is expressed in terms of Gell-Mann matrices that break down as three spin operators and five nematic (quadrupole) order operators. Mean-field phase diagram exhibits a rich structure including anti-ferro-orbital, ferro-orbital, and both single and multiple spiral-orbital phases. Superexchange calculation for spinful, two-orbital model also strongly suggests a robust chiral-orbital order in the ground state.
Cite
@article{arxiv.1212.0932,
title = {Orbital Dzyaloshinskii-Moriya Exchange Interaction},
author = {Panjin Kim and Jung Hoon Han},
journal= {arXiv preprint arXiv:1212.0932},
year = {2013}
}
Comments
6 pages, 1 figure