Transverse rectification in density-modulated two-dimensional electron   gases
  We demonstrate tunable transverse rectification in a density-modulated two-dimensional electron gas (2DEG). The density modulation is induced by two surface gates, running in parallel along a narrow stripe of 2DEG. A transverse voltage in the direction of the density modulation is observed, i.e. perpendicular to the applied source-drain voltage. The polarity of the transverse voltage is independent of the polarity of the source-drain voltage, demonstrating rectification in the device. We find that the transverse voltage $U_{y}$ depends quadratically on the applied source-drain voltage and non-monotonically on the density modulation. The experimental results are discussed in the framework of a diffusion thermopower model. 
A. Ganczarczyk, S. Rojek, A. Quindeau, M. Geller, A. Hucht, C.   Notthoff, D. Reuter, A. D. Wieck, J. K\"onig, and A. Lorke