Local Magnetoresistance at Room Temperature in Si $\langle100\rangle$ Devices

We show that there is a crystal orientation effect on the two-terminal local magnetoresistance (MR) in silicon (Si)-based lateral spin-valve (LSV) devices. When we compare the local MR effect between Si $\langle 100\rangle $ and Si $\langle 110\rangle $ LSV devices, the magnitude of the local MR signals for Si $\langle 100\rangle $ LSV devices is always larger than that for Si $\langle 110\rangle $ LSV devices. For Si $\langle 100\rangle $ LSV devices, the magnitude of the room-temperature MR ratio reaches approximately 0.06%. We infer that it is important to consider the tunneling anisotropic spin polarization, which is due to the magnetization direction of the ferromagnetic contacts relative to the Si crystal orientation, in the fabricated LSV devices.