The Landau level density of states as a function of Fermi energy in the two dimensional electron gas

We have made quantitative determinations of the density of states (DOS) of Landau levels in a 2d system whose density can be varied using a gate bias. A novel technique employs two normalization conditions to extract the DOS as a function of Fermi energy in the 2d electron gas from capacitance data. No knowledge of sample parameters is required except for the sample area. In contrast with previous results, we find that Lorentzian lineshapes give excellent fits to the Landau level structure without need for added background and with linewidths that are independent of magnetic field strength.