Magnetothermopower in a Corbino Quantum Hall Device

摘要

A Corbino configuration in combination with a moveable heater was used to examinethe magnetothermopower of a two-dimensional electron system. The Corbino thermopowergives direct access to the longitudinal component of the thermoelectric tensor. Under theprevailing condition of phonon drag this component should be equal to zero. However, a largethermopower was measured, which was shown to be a result of growth induced anisotropiesin the GaAs/AlGaAs heterojunction. Using the ability to move the heater an image was madeof the thermovoltage across the sample. A novel segmented Corbino geometry was employedto examine the anisotropy directly.