Novel Technique for Determination of the Landau Level Density of States as a Function of Fermi Energy in the Two-Dimentional Electron Gas

Abstract

This paper introduces a new technique for obtaining a quantitative description of the magnetic field density of states (DOS) in the two-dimensional (2d) electron gas. The density of states of a 2d electron gas in a magnetic field oriented perpendicular to the plane of the electron gas is ideally made up of delta function Landau level DOS peaks. These broaden under the influence of scattering. The shape and size of these peaks has been of considerable experimental and theoretical interest over the last two decades (Ando et al., 1982, and references therein). In our samples the electron density in the 2d gas may be varied by means of a gate bias. Two samples have densities variable from 0 – 4 × 1011 cm-2, and another is variable from 0 – 6 × 1011 cm-2. Through the use of a “lever-arm, “ determined from analysis of our data, which converts this gate bias to Fermi energy in the 2d gas, we are able to plot the DOS as a function of Fermi energy. This contrasts with previous DOS studies which have typically measured the DOS at fixed density of the 2d gas.KeywordsFermi EnergyLandau LevelGate BiasTunnel BarrierGround State WavefunctionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.