Electrical Control of Magnetoresistance In a InP-Based Lateral Spin Valve with a Two-Dimensional Electron Gas (2-DEG) Channel

Electrical field control of spin transport has been of recent interest. The control of magnetoresistance of a lateral InP-based spin valve consisting of a InAs/In$_{0.53}$Ga$_{0.47}$As/In$_{0.52}$Al$_{0.48}$As 2-DEG channel with a gate electrode is demonstrated. The polarizer and analyzer are made with MnAs/In$_{0.52}$Al$_{0.48}$As Schottky tunnel barriers and the Ti/Au gate electrode is placed outside the channel region, of length 0.6 $\mu $m, and alongside the polarizer. The magnetoresistance changes from 0.14 to 4{\%} at 10 K, when the gate bias is changed from 0 to 8V, in a device in which the magnetization of the polarizer and analyzer is in the direction of spin transport in the 2-DEG. The effect is absent in a GaAs channel spin valve and other control devices, indicating that the observed change in magnetoresistance in the 2-DEG spin valve is due to Rashba spin-orbit coupling. The results will be compared with those obtained from spin valves in which the gate is placed directly above the local spin valve channel region.