Efficient spin transport along Si $\langle$100$\rangle$ at room temperature

TL;DR

This study demonstrates enhanced room-temperature spin transport in silicon lateral spin valves when oriented along the 000 direction, linking spin detection efficiency to silicon's crystallographic orientation.

Contribution

It reveals that changing silicon channel orientation to 000 significantly improves spin signal magnitude and detection efficiency at room temperature.

Findings

Spin signals are markedly enhanced in Si000 LSVs.

Spin injection/detection efficiency is higher in Si000 than in Si000.

Crystallographic orientation of silicon influences spin detection efficiency.

Abstract

We find efficient spin transport in Si at room temperature in lateral spin valves (LSVs). When the crystal orientation of the spin-transport channel in LSVs is changed from $\langle$110$\rangle$, which is a conventional cleavage direction, to $\langle$100$\rangle$, the maximum magnitude of the spin signals is markedly enhanced. From the analyses based on the one-dimensional spin diffusion model, we can understand that the spin injection/detection efficiency in Si$\langle$100$\rangle$ LSVs is larger than that in Si$\langle$110$\rangle$ ones. We infer that, in Si-based LSVs, the spin detection efficiency of the pure spin current is related to the crystallographic orientation of the valley structures of the conduction band in Si.