I-V Characteristics at Small Landau Level Filling Factors in High Quality GaAs/AlGaAs Heterostructures

We studied current-voltage characteristics in high-mobility (up to micron ~7x10 sup 6 cm sup 2 /Vsec), low-density (n1x10 sup 11 cm-2) Ga/AlGaAs heterostructures in the high-magnetic field limit. These samples have shown striking temperature dependences of the transport coefficients at small filling factors ( nu ~1/3) which could be attributed to either single particle localization or Wigner crystallization. sup 1