We report on a study of the temperature and Zeeman-coupling-strength dependence of the one-particle Green’s function of a two-dimensional (2D) electron gas at a Landau-level filling factor $\nu =1,$ where the ground state is a strong ferromagnet. Our work places emphasis on the role played by the itinerancy of the electrons which carry the spin magnetization, and on analogies between this system and conventional itinerant electron ferromagnets. We go beyond self-consistent-field theory by evaluating the one-particle Green’s function using a self-energy, which accounts for quasiparticle spin-wave interactions. Our calculations predict a sharp peak at a large bias voltage in the 2D-2D tunneling current, with an integrated strength that increases approximately linearly with temperature. We compare calculated properties with experiment, where available, and with predictions based on numerical exact diagonalization and other theoretical approaches.

• Received 6 March 2000

DOI:https://doi.org/10.1103/PhysRevB.62.2640