Two-dimensional Ising physics in quantum Hall ferromagnets

The close analogy between two-dimensional electron system states and conventional itinerant ferromagnets is used to analyze ordered many-body states in the integer quantum Hall regime. The possibility of in situ tuning between easy-plane and easy-axis quantum Hall ferromagnets is discussed for biased bilayer systems with total filling factor ν=3. Recent experiments on Ising quantum Hall systems are explained in terms of their unique domain wall physics. Issues including Ising critical temperatures, hysteresis loops and transport anisotropies are addressed using a combination of the self-consistent field technique, Hartree–Fock/RPA approximation, and exact diagonalization of the many-body Hamiltonian.