The Onset of Anisotropic Transport of Two-Dimensional Electrons in High Landau Levels: An Isotropic-to-Nematic Liquid Crystal Phase Transition?

The recently discovered anisotropy of the longitudinal resistance of two-dimensional electrons near half filling of high Landau levels is found to persist to much higher temperatures T when a large in-plane magnetic field B|| is applied. Under these conditions we find that the longitudinal resistivity scales quasi-linearly with B||/T. These observations support the notion that the onset of anisotropy at B||=0 does not reflect the spontaneous development of charge density modulations but may instead signal an isotropic-to-nematic liquid crystal phase transition.