Magnetoconductance Autocorrelation Function for Few--Channel Chaotic Microstructures

Abstract Using the Landauer formula and a random matrix model, we investigate the autocorrelation function of the conductance versus magnetic field strength for ballistic electron transport through few-channel microstructures with the shape of a classically chaotic billiard coupled to ideal leads. This function depends on the total numberMof channels and the parametertwhich measures the difference in magnetic field strengths. Using the supersymmetry technique, we calculate for any value ofMthe leading terms of the asymptotic expansion for smallt. We pay particular attention to the evaluation of the boundary terms. For small values ofM, we supplement this analytical study by a numerical simulation. We compare our results with the squared Lorentzian suggested by semiclassical theory and valid for largeM. For smallM, we present evidence for non-analytic behavior of the autocorrelation function att=0.