THERMOMAGNETIC TRANSPORT-COEFFICIENTS OF A PERIODICALLY MODULATED 2-DIMENSIONAL ELECTRON-GAS

The impurity contribution to the thermopower and thermal conductivity of a two-dimensional electron gas that is modulated weakly and periodically along the x direction is evaluated in the presence of a perpendicular magnetic field. A type of oscillations, having the same origin as the magnetoresistance oscillations discovered recently, is predicted. The thermopower components Sxx, Syy, and Sxy all oscillate in phase in small magnetic fields. The oscillations in the thermal conductivity Kxx are shifted by /2 with respect to those oscillations in Sxx. $K sub xx oscillates out of phase with Kyy and Kxy. © 1990 The American Physical Society.