▎ 摘　　要

The temperature dependence of the spin relaxation time tau(s) in multilayer graphene (MLG) spin valve devices was measured using a non-local magnetoresistance (NLMR) measurement. A weak localization (WL) was observed from magnetoresistance (MR) measurements below similar to 70 K, suggesting coherent transport of the charge carriers. Within the same temperature range, we observed a large increase in the spin relaxation time tau(s) and spin diffusion length lambda(s) even though the diffusion constant D-s was suppressed by the WL. This demonstrated that the spin relaxation time in MLG could be significantly extended when the charge experiences quantum interference effect in the coherent charge transport regime. (C) 2013 The Japan Society of Applied Physics