The spin polarization (P) of high-density InSb two-dimensional electron systems (2DESs) has been measured using both parallel and tilted magnetic fields. P is found to exhibit a superlinear increase with the total field B. This P-B nonlinearity results in a difference in spin susceptibility between its real value Xs and Xgm ~ m*g*(m* and g* are the effective mass and g factor, respectively) as routinely used in experiments. We demonstrate that such a P-B nonlinearity originates from the linearly P-dependent g* due to the exchange coupling of electrons rather than from the electron correlation as predicted for the low-density 2DES.
@article{arxiv.1006.3456,
title = {Nonlinear magnetic field dependence of spin polarization in high density two-dimensional electron systems},
author = {K. F. Yang and H. W. Liu and T. D. Mishima and M. B. Santos and K. Nagase and Y. Hirayama},
journal= {arXiv preprint arXiv:1006.3456},
year = {2011}
}