New Anisotropic Behavior of Quantum Hall Resistance in (110) GaAs Heterostructures at mK Temperatures and Fractional Filling Factors

Abstract

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 bears some similarity with what is already seen at half-odd-integer filling on (001) oriented substrates. In addition we report the first observation of transport anisotropies within the lowest Landau-Level. This remarkable new anisotropy is independent of the current direction and depends on the polarity of the magnetic field.Comment: 3 Pages, 4 figures, Latex, uses elsart.cls and physart.cls, to be published in Physica E Added reference, made contact configuration more clea