Self-consistent modelling based on local spin-density formalism is employed to calculate conductance of quantum point contacts at finite temperatures. The total electrostatic potential exhibits spin-dependent splitting, which persists at temperatures up to 0.5 K and gives rise to the anomalies at 0.4 and 0.7 of the conductance quantum 2e2/h occurring simultaneously in the absence of external magnetic fields.
@article{arxiv.cond-mat/0703323,
title = {0.4 and 0.7 conductance anomalies in quantum point contacts},
author = {A. M. Bychkov and T. M. Stace},
journal= {arXiv preprint arXiv:cond-mat/0703323},
year = {2007}
}