Robustness of Spin Polarization in Graphene‐Based Spin Valves

TLDR

Spin polarization in spintronic devices decreases under bias voltage, a critical issue that must be addressed. The robustness of spin polarization in multilayer‑graphene spin valves is due to reduced spin scattering at an ideal interface. Multilayer‑graphene spin valves maintain constant spin polarization up to +2.7 V and –0.6 V at room temperature, outperforming all other devices, and the observed double signal intensity in local versus nonlocal measurements confirms theoretical predictions.

Abstract

Abstract The decrease of spin polarization in spintronics devices under the application of a bias voltage is one of a number of currently important problems that should be solved. Here, an unprecedented robustness of the spin polarization in multilayer‐graphene spin valves at room temperature is revealed. Surprisingly, the spin polarization of injected spins is constant up to a bias voltage of +2.7 V and −0.6 V in positive‐ and negative‐bias voltage applications at room temperature, respectively, which is superior to all spintronics devices. This finding is induced by suppression of spin scattering due to an ideal‐interface formation. Furthermore, an important accordance between theory and experiment in molecular spintronics is found by observing the fact that the signal intensity in a local scheme is double that in a nonlocal scheme, as theory predicts, which provides construction of a steadfast physical basis in this field.