Rashba spin–orbit coupling enhanced anomalous Hall effect in MnxSi1−x/SiO2/Si p–i–n junctions

Abstract

Rashba spin–orbit coupling, which allows the manipulation of electron spins in semiconductor heterostructures, has attracted great interest due to its potential applications in spintronic devices. But it is still not clear whether the Rashba spin–orbit coupling in a p–n junction can have a significant effect on the anomalous Hall effect of a p-type ferromagnetic semiconductor film grown on an n-type semiconductor substrate. Here Mn_xSi_1−x/SiO₂/Si p–i–n junctions were formed by sputtering p-type Mn_xSi_1−x magnetic semiconductor films on near-intrinsic n-type Si substrates with about 1 nm SiO₂ native oxide layer. Although Mn_0.48Si_0.52/SiO₂/Si p–i–n junctions and Mn_0.48Si_0.52 magnetic semiconductor films grown on insulating glass substrates almost show the same positive anomalous Hall effect at low temperature below 150 K, Mn_0.48Si_0.52/SiO₂/Si p–i–n junctions show a greatly enhanced negative anomalous Hall effect around the temperature of 200 K. On further analysis of the in-plane resistance of Mn_0.48Si_0.52 films and the I–V curves of the p–i–n junctions, the enhanced negative anomalous Hall effect is attributed to the interfacial Rashba spin–orbit coupling in Mn_0.48Si_0.52/SiO₂/Si p–i–n junctions.