Spin transport in multilayer graphene away from the charge neutrality point

Abstract

Graphene is considered as a promising material in spintronics due to its long spin relaxation time and long spin relaxation length. However, its spin transport properties have been studied at low carrier density only, beyond which much is still unknown. In this study, we explore the spin transport and spin precession properties in multilayer graphene at high carrier density using ionic liquid gating. We find that the spin relaxation time is directly proportional to the momentum relaxation time, indicating that the Elliott-Yafet mechanism still dominates the spin relaxation in multilayer graphene away from the charge neutrality point.

Nonlocal Spin Valves Based on Graphene/Fe3GeTe2 van der Waals Heterostructures

“…Hence, we assumed a typical value of λ G (∼1.5 μm) for multilayer graphene by referring to our previous study. 47 Moreover, ΔR NL was ∼1.5 mΩ (Figure 2b), σ G was measured to be 6.1 mS, W was ∼2.5 μm, and L was ∼3 μm, so P J was calculated to be about 1%, close to the result achieved from the NLSV with transparent contacts. 48 Such a low injection efficiency could be attributed to two factors: first, there was still a conductivity mismatch between FGT and multilayer graphene, and thus the backflow of spins could not be avoided completely.…”

“…Since the Hanle effect was absent in our experiment, the spin relaxation length could not be determined. Hence, we assumed a typical value of λ G (∼1.5 μm) for multilayer graphene by referring to our previous study . Moreover, Δ R NL was ∼1.5 mΩ (Figure b), σ G was measured to be 6.1 mS, W was ∼2.5 μm, and L was ∼3 μm, so P J was calculated to be about 1%, close to the result achieved from the NLSV with transparent contacts .…”