%0 Journal Article
%T Measurements of the Composite Fermion masses from the spin polarization of 2-D electrons in the region $1<¦Í<2$
%A R. Chughtai
%A V. Zhitomirsky
%A R. J. Nicholas
%A M. Henini
%J Physics
%D 2001
%I arXiv
%R 10.1103/PhysRevB.65.161305
%X Measurements of the reflectivity of a 2-D electron gas are used to deduce the polarization of the Composite Fermion hole system formed for Landau level occupancies in the regime 1<\nu<2. The measurements are consistent with the formation of a mixed spin CF system and allow the density of states or `polarization' effective mass of the CF holes to be determined. The mass values at \nu=3/2 are found to be ~1.9m_{e} for electron densities of 4.4 x 10^{11} cm^{-2}, which is significantly larger than those found from measurements of the energy gaps at finite values of effective magnetic field.
%U http://arxiv.org/abs/cond-mat/0111492v1