Spin-dependent transport properties in heavy-metal adatom decorated graphene nanoribbons

Abstract

We apply the non-equilibrium Green’s function (NEGF) method to study spin transport properties of graphene nanoribbons decorated with Gold (Au) and Thallium (Tl) adatoms. Both the enhanced intrinsic SOC and Rashba SOC induced by adatoms makes a huge impact and changes the spin-dependent transport properties such as spin relaxation, charge distribution, and electrical conductivity in the adatom armchair graphene nanoribbons (AGNR) system. Our results examine the Quantum Spin Hall phase in Tl adatom AGNR, and also support that the Rashba effect induced by Au adatom is harmful for the stabilizing of QSH phase. Furthermore, a faster spin-relaxation in Au adatom AGNR system is also demonstrated in our study. The comparison of these spin-dependent effects in different adatoms systems would help us to clarify the influences of the enhanced intrinsic SOC and Rashba SOC in graphene, and pave the way for manipulating graphene-based spintronic devices. In the end, we summarized and discussed the spin-dependent transport properties of several heavy-metal decorated graphene systems.