Doping-dependent magnetization plateaux in p-merized Hubbard chains
Abstract
We study zero-temperature Hubbard chains with periodically modulated hopping at arbitrary filling n and magnetization m. We show that the magnetization curves have plateaux at certain values of m which depend on the periodicity p and the filling. At commensurate filling n a charge gap opens and then magnetization plateaux correspond to fully gapped situations. However, plateaux also arise in the magnetization curves at fixed n between the commensurate values and then the plateau-value of of m depends continuously on n and can thus also become irrational. In particular for the case of dimerized hopping (p=2) and fixed doping we find that a plateau appears at m=1-n. In this case, there is still a gapless mode on the plateau leading to thermodynamic behavior which is different from a completely gapped situation.
Cite
@article{arxiv.cond-mat/9908398,
title = {Doping-dependent magnetization plateaux in p-merized Hubbard chains},
author = {D. C. Cabra and A. De Martino and A. Honecker and P. Pujol and P. Simon},
journal= {arXiv preprint arXiv:cond-mat/9908398},
year = {2009}
}
Comments
9 pages REVTeX, 3 PostScript figures included using psfig.sty; this is the final version to appear in Phys. Lett. A; substantial changes: Lanczos part removed to gain space for further explanations (refer to original version for details on the numerics)