Field effect in InAs/permalloy hybrid transistors

We measure the static and dynamic resistance of metal-oxide-semiconductor field-effect transistors with ferromagnetic source and drain contacts deposited on InAs at liquid helium and elevated temperatures. The field effect is examined as a function of the applied gate voltage in external magnetic fields applied in plane either parallel or perpendicular to the current direction. In the parallel configuration the resistance exhibits strong evidence for spin-polarized transport via an oscillatory gate-voltage dependence of the resistance jumps at the irreversible magnetization reversals of the ferromagnetic electrodes. Furthermore, transport measurements in external magnetic fields aligned perpendicular to the substrate surface are performed up to strengths of 14 T to investigate the properties of the semiconductor channel, i.e., charge-carrier concentration, electron mobility, and weak localization.