SLIGHTLY NONIDEAL 2D FERMI GAS IN A MAGNETIC-FIELD

The properties of a slightly nonideal 2D Fermi gas in a magnetic field are analyzed by a Feynman-diagram technique. Expressions for the eige nenergy part of the one-particle Green's function are derived in up to second-order perturbation theory. Because the spectrum of the 2D part icles is discrete in a magnetic field, there is no attenuation of the quasiparticles, and there is a splitting of seed Landau levels. The ei genenergy part has a pole at zero frequency. The maximum filling facto r for each sublevel is v(max) = 1/2.