Probing the Spin-Momentum Locking in Rashba Surfaces via Spin Current

Abstract: In this work, we explore the intriguing spin-momentum locking phenomenon within the Rashba states of antimony (Sb) films. By combining spin pumping with the flow of an external charge current, we reveal the topological properties of surface states in Sb films. Taking advantage of the well-defined spin polarization of both spin-momentum-locked charge currents and spin-pumped currents, we demonstrate precise manipulation over the direction and magnitude of the resulting charging current, generated through the inverse Rashba-Edelstein effect. This fascinating phenomenon is attributed to the dynamic interaction between the accumulation of out-of-equilibrium pumped spins and the flowing spins, intrinsically locked perpendicular to the direction of the charge current. The results show that Sb as a promising material for basic and applied investigation of spintronics phenomena. We believe that the nanostructures investigated here open the way for the development of low-power logic gates operating in the range of a few tens of microamperes.