Spin-orbit coupling effect on quantum Hall ferromagnets with vanishing Zeeman energy

We present the phase diagram of a ferromagnetic nu = 2N + 1 quantum Hall liquid in a narrow quantum well with vanishing single-particle Zeeman splitting, epsilon(Z), and a pronounced spin-orbit coupling. Upon decreasing epsilon(Z) the spin-polarization field of a liquid takes, first, the easy-axis configuration, followed by the formation of a helical state which affects the transport and NMR properties of a liquid and the form of topological defects in it.