Two-dimensional magneto-quantum transport on GaAs-Al_xGa_1-xAs heterostructures under non-ohmic conditions

Abstract

Measurements of the conductivity sigma xx in the minima of the Shubnikov-de Haas oscillations on GaAs-AlxGa1-xAs heterostructures show that at helium temperatures a strong non-ohmic behaviour is observed with an instability in the current-voltage characteristic at electric field values of about 100 V cm-1 at B=7T. The data are analysed on the basis of an electric-field-dependent electron temperature.