Anomalous scaling of conductivity in integrable fermion systems
Abstract
We analyze the high-temperature conductivity in one-dimensional integrable models of interacting fermions: the t-V model (anisotropic Heisenberg spin chain) and the Hubbard model, at half-filling in the regime corresponding to insulating ground state. A microcanonical Lanczos method study for finite size systems reveals anomalously large finite-size effects at low frequencies while a frequency-moment analysis indicates a finite d.c. conductivity. This phenomenon also appears in a prototype integrable quantum system of impenetrable particles, representing a strong-coupling limit of both models. In the thermodynamic limit, the two results could converge to a finite d.c. conductivity rather than an ideal conductor or insulator scenario.
Keywords
Cite
@article{arxiv.cond-mat/0403323,
title = {Anomalous scaling of conductivity in integrable fermion systems},
author = {P. Prelovsek and S. El Shawish and X. Zotos and M. Long},
journal= {arXiv preprint arXiv:cond-mat/0403323},
year = {2009}
}
Comments
6 pages, 3 figures. Submitted to PRB