Weak localization of bismuth cluster-decorated graphene and its spin–orbit interaction

Abstract

Weak-localization (WL) measurements were performed in a Bi cluster-decorated graphene sheet. The charge concentration was kept constant, and the amplitude of the conductance correction was suppressed after the Bi-cluster deposition. Detailed WL data were obtained while the gate and temperature were changed. Using E. McCann’s formula, the spin-relaxation time was extracted, which was found to increase with the elastic scattering time. This is attributed to the Elliott–Yafet spin relaxation and Kane–Mele type spin–orbit coupling (SOC). The SOC strength was enhanced to 2.64 meV as a result of the first deposition. The coverage effect is discussed according to the measurement after the second deposition.