We study quantum Hall systems (mainly the integer case) at finite temperatures and show that there is a novel temperature dependence even for a pure system, thanks to the `anomalous' nature of generators of translation. The deviation of Hall conductivity from its zero temperature value is controlled by a parameter T0=πρ/m∗N which is sample specific and hence the universality of quantization is lost at finite temperatures.
@article{arxiv.cond-mat/9507125,
title = {Novel Finite Temperature Conductivity in Quantum Hall Systems},
author = {Sudhansu S. Mandal and S. Ramaswamy and V. Ravishankar},
journal= {arXiv preprint arXiv:cond-mat/9507125},
year = {2007}
}