Spin-dependent fractional QHE states in the N=0 Landau level

Spin assignments of fractional QHE states in the N=0 Landau level are determined from finite-size calculations of the Coulomb energy. There is a spin-unpolarised ground state at 2 / 3 filling, with partial polarisation at 3 / 5 filling and full polarisation at 1/q filling with q odd. This explained in terms of competition between Coulomb repulsion, exchange and interaction of unlike spins. The experimental consequences are briefly discussed.