Charge ordering in theta-(BEDT-TTF)_2 X materials
Abstract
We investigate theoretically charge ordered states on the anisotropic triangular lattice characteristic of the theta-(BEDT-TTF)_2 X materials. Using exact diagonalization studies, we establish that the charge order (CO) pattern corresponds to a ``horizontal'' stripe structure, with ...1100... CO along the two directions with larger electron hopping (p-directions), and ...1010... CO along the third direction (c-direction). The CO is accompanied by co-operative bond dimerizations along all three directions in the highest spin state. In the lowest spin state bonds along the p-directions are tetramerized. Our theory explains the occurence of a charge-induced high temperature transition as well as a spin gap transition at lower temperature.
Cite
@article{arxiv.cond-mat/0203266,
title = {Charge ordering in theta-(BEDT-TTF)_2 X materials},
author = {R. T. Clay and S. Mazumdar and D. K. Campbell},
journal= {arXiv preprint arXiv:cond-mat/0203266},
year = {2009}
}
Comments
4 pages, 4 eps figures, uses jpsj2.cls