Transport property of insulating barrier in a ferromagnet-semiconductor hybrid system

Abstract

Two-dimensional electron gas layer is essential for a developing spin-FET because of its high mobility and large spin–orbit coupling. The junction properties between a ferromagnet (FM) and a 2-DEG system are the most important factor. Two types of a 2-DEG layer, an InAs and a GaAs channel heterostructures, are fabricated to compare the junction properties of the two systems. A GaAs-based channel 2-DEG layer with Al2O3 tunneling layer using a new oxidization method is prepared. During the heat treatment at the furnace, the arsenic gas was evaporated and the top AlAs layer was converted to the aluminum oxide layer. An InAs channel 2-DEG layer with a semiconductor-based barrier and FM junction shows the ohmic behavior. In the potentiometric measurement, a spin–orbit coupling of 2-DEG layer is observed in the interface between a FM and an InAs channel 2-DEG layer, which proves the efficient spin transport junction.