arXiv subjects
Publications and source records attributed to R. J. Hyndman.
We explain for the first time thermopower data for p-type GaAs/AlGaAs layers. The data span a temperature range between 0.2 to 1.2K. We calculate both the diffusion $S^{d}$ and the phonon-drag $S^{g}$ contributions to the thermopower. We find that $S^{d}$ is significant for temperatures up to 0.3K while at higher temperatures $S^{g}$ dominates. The calculated and measured $S^{g}$ agree very well with no adjustable parameters.
We report anomalous behavior in a double-layer two dimensional hole gas (2DHG) at even integer filling factors which includes hysteresis in the longitudinal and Hall resistances and a very weak temperature dependence of the resistance minima. All anomalies disappear and the conventional quantum Hall effect behavior recovers when a thin metal film is placed on top of the 2DHG. The behavior is attributed to presence of the theoretically predicted magnetic ordering at even integer filling factors which causes the formation of macroscopic spin-charge domains.