Luttinger liquid superlattices: realization of gapless insulating phases
Abstract
We investigate Luttinger Liquid superlattices, a periodic structure composed of two kinds of one-dimensional systems of interacting electrons. We calculate several properties of the low-energy sector: the effective charge and spin velocities, the compressibility, various correlation functions, the Landauer conductance and the Drude weight. The low-energy properties are subsumed into effective parameters, much like homogeneous one-dimensional systems. A generic result is the weighted average nature of these parameters, in proportion to the spatial extent of the underlying subunits, pointing to the possibility of ``engineered'' structures. As a specific realization, we consider a one-dimensional Hubbard superlattice, which consists of a periodic arrangement of two long Hubbard chains with different coupling constants and different hopping amplitudes. This system exhibits a rich phase diagram with several phases, both metallic and insulating. We have found that gapless insulating phases are present over a wide range of parameters.
Keywords
Cite
@article{arxiv.cond-mat/0201017,
title = {Luttinger liquid superlattices: realization of gapless insulating phases},
author = {J. Silva-Valencia and E. Miranda and Raimundo R. dos Santos},
journal= {arXiv preprint arXiv:cond-mat/0201017},
year = {2007}
}
Comments
16 pages, 15 figures, RevTeX4