Influence of Ohmic Contacts on the Amplitude of Shubnikow-de Haas Oscillations

Zusammenfassung

The longitudinal magnetoresistance of a two- dimensional electron gas is shown to be strongly dependent on the presence of ohmic contacts between the voltage probes. By connecting or disconnecting contacts with additional gates across the potential probes it is possible to drastically change the amplitude of Shubnikov-de Haas oscillations.