Quasiparticle properties of quantum Hall ferromagnets

We report on a study of the temperature and Zeeman-coupling-strength depend ence of the one-particle Green's function of a two-dimensional (2D) electro n gas at a Landau-level tilling factor v = 1, where the ground state is a s trong ferromagnet. Our work places emphasis on the role played by the itine rancy of the electrons which carry the spin magnetization, and on analogies between this system and conventional itinerant electron ferromagnets. We g o beyond self-consistent-held theory by evaluating the one-particle Green's function using a self-energy, which accounts for quasiparticle spin-wave i nteractions. 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 w ith experiment, where available, and with predictions based on numerical ex act diagonalization and other theoretical approaches.