The Role of Surface Treatment in the Field Effect Anomaly of n-Type Insb at High Magnetic Fields

摘要

By applying a magnetic field perpendicular to the surface of n-type InSb during a classical field effect experiment, a decrease in surface conductance was observed as contrasted to the expected field effect increase in conductance. This anomaly in the field effect was found in the case of cleaved $110$ as well as etched $111$ surfaces at 77K both in vacuum or immersed in liquid nitrogen. In the case of the $110$ surfaces the anomaly was also observed at 4.2K in vacuum but not when they were immersed in liquid helium. The anomaly was not present at 4.2K in the case of $111$ surfaces either in vacuum or when they were immersed in liquid helium. The results are explained on the basis of cross quantization of the kinetic energy of the electrons by the narrow surface space charge potential barrier normal to the surface and the magnetic orbital quantization on a plane parallel to the surface. (The symbol $ is used here to indicate brackets). (Author)