6 papers
Four-point measurements of n- and p-type two-dimensional systems fabricated with cleaved-edge overgrowth
M. Grayson, S. F. Roth, Y. Xiang +3
We demonstrate a contact design that allows four-terminal magnetotransport measurements of cleaved-edge overgrown two-dimensional electron and hole systems. By lithographically pat…
Anomalous magnetoresistance peak in (110) GaAs two-dimensional holes: Evidence for Landau-level spin-index anticrossings
F. Fischer, R. Winkler, D. Schuh +2
We measure an anomalous magnetoresistance peak within the lowest Landau level (nu = 1) minimum of a two-dimensional hole system on (110) GaAs. Self-consistent calculations of the v…
Influence of voltmeter input impedance on quantum Hall effect measurements
F. Fischer, M. Grayson
We report on the influence of voltmeters on measurements of the longitudinal resistance in the quantum Hall effect regime. We show that for typical input resistances for standard d…
Modulating the growth conditions: Si as an acceptor in (110) GaAs for high mobility p-type heterostructures
F. Fischer, M. Grayson, D. Schuh +2
We implement metallic layers of Si-doped (110) GaAs as modulation doping in high mobility p-type heterostructures, changing to p-growth conditions for the doping layer alone. The s…
Measuring carrier density in parallel conduction layers of quantum Hall systems
M. Grayson, F. Fischer
An experimental analysis for two parallel conducting layers determines the full resistivity tensor of the parallel layer, at magnetic fields where the other layer is in the quantum…
New Anisotropic Behavior of Quantum Hall Resistance in (110) GaAs Heterostructures at mK Temperatures and Fractional Filling Factors
Frank Fischer, Matthew Grayson, Erwin Schuberth +3
Transport experiments in high mobility (110) GaAs heterostructures have been performed at very low temperatures 8 mK. At higher Landau-Levels we observe a transport anisotropy that…