Alternating Spin and Orbital Dimerization in Strong-coupling Two-band Models
Abstract
We study a one-dimensional Hamiltonian consisting of coupled SU(2) spin and orbital degrees of freedom. Using the density matrix renormalization group, we calculate the phase-diagram and the ground state correlation functions for this model. We find that, in addition to the ferromagnetic and power-law antiferromagnetic phases for spin and orbital degrees of freedom, this model has a gapless line extending from the ferromagnetic phase to the Bethe ansatz solvable SU(4) critical point, and a gapped phase with doubly degenerate ground states which form alternating spin and orbital singlets. The spin-gap and the order parameters are evaluated and the relevance to several recently discovered spin-gap materials is discussed.
Cite
@article{arxiv.cond-mat/9807270,
title = {Alternating Spin and Orbital Dimerization in Strong-coupling Two-band Models},
author = {Swapan K. Pati and Rajiv R. P. Singh and Daniel I. Khomskii},
journal= {arXiv preprint arXiv:cond-mat/9807270},
year = {2009}
}
Comments
4 pages REVTEX and 4 Postscript figures