Holes as Dipoles in a Doped Antiferromagnet and Stripe Instabilities
Abstract
Based on an effective model of a doped antiferromagnetic Mott insulator, we show that a doped hole will induce a dipole-like spin configuration in a spin ordered phase at low doping. The kinetic energy of doped holes is severely frustrated and a hole-dipole object is actually localized or self-trapped in space. Without a balance from the kinetic energy, the long-range dipole-dipole interaction between doped holes will dominate the low-energy physics, leading to an inhomogeneity instability as hole-dipoles collapse into stripes. Both antiphase metallic stripes of quarter-filling and antiphase insulating stripes along a diagonal direction are discussed as composed of hole-dipoles as elementary building blocks. Stripe melting and competing phases are also discussed.
Cite
@article{arxiv.cond-mat/0212134,
title = {Holes as Dipoles in a Doped Antiferromagnet and Stripe Instabilities},
author = {Su-Peng Kou and Zheng-Yu Weng},
journal= {arXiv preprint arXiv:cond-mat/0212134},
year = {2007}
}
Comments
11 pages, 5 figures, revised version with reference updates, to appear in Phys. Rev. B