Half-polarized quantum Hall states

We report a theoretical analysis of the half-polarized quantum Hall states observed in a recent experiment Our numerical results indicate that the gro und state energy of the quantum Hall nu = 2/3 and nu = 2/5 States versus sp in polarization has a downward cusp at half the maximal spin polarization. We map the two-component fermion system onto a system of excitons and descr ibe the ground state as a liquid state of excitons with nonzero values of e xciton angular momentum.