A low energy action for double-layer quantum Hall systems at filling fractions ν=2/m (m an odd integer) is introduced. Interlayer antiferromagnetic exchange induces a phase with canted spin order, and also a spin-singlet phase. Universal properties of zero and finite temperature transitions are obtained. We compute the critical temperature at which the canted order vanishes in a Kosterlitz-Thouless transition. Implications for recent light scattering experiments at ν=2 are noted.
@article{arxiv.cond-mat/9701142,
title = {Double-layer quantum Hall antiferromagnetism at filling fraction nu=2/(odd integer)},
author = {S. Das Sarma and Subir Sachdev and Lian Zheng},
journal= {arXiv preprint arXiv:cond-mat/9701142},
year = {2009}
}