We have experimentally studied the non-equilibrium transport in low-density clean 2D electron systems at mesoscopic length scales. At zero magnetic field (B), a double-peak structure in the non-linear conductance was observed close to the Fermi energy in the localized regime. From the behavior of these peaks at non-zero B, we could associate them to the opposite spin states of the system, indicating a spontaneous spin polarization at B = 0. Detailed temperature and disorder dependence of the structure shows that such a splitting is a ground state property of the low-density 2D systems.
@article{arxiv.cond-mat/0310628,
title = {Possible evidence of a spontaneous spin-polarization in mesoscopic 2D electron systems},
author = {A. Ghosh and C. J. B. Ford and M. Pepper and H. E. Beere and D. A. Ritchie},
journal= {arXiv preprint arXiv:cond-mat/0310628},
year = {2009}
}