Probing the Spin-Momentum Locking on Rashba Surfaces via Spin Current.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Spin-momentum locking is a quantum mechanical phenomenon where electron spin is tied to its momentum.
• The Rashba effect describes spin-orbit interaction in systems lacking inversion symmetry, leading to spin-split energy bands.
• Antimony (Sb) is a heavy element with potential for topological surface states and spintronic applications.

Purpose of the Study:

• To investigate the spin-momentum locking phenomenon on Rashba states in antimony (Sb) films.
• To uncover the topological properties of Sb surface states using spin pumping and external charge current.
• To demonstrate the precise manipulation of charge currents via the inverse Rashba-Edelstein effect.

Main Methods:

• Spin pumping experiments to generate non-equilibrium spin accumulation.
• Application of external charge current to probe spin-momentum locking.
• Utilizing the inverse Rashba-Edelstein effect to convert spin accumulation into charge current.
• Analysis of dynamic interactions between pumped spins and spin-momentum-locked spins.

Main Results:

• Demonstrated precise control over the direction and magnitude of charge current generated by the inverse Rashba-Edelstein effect in Sb films.
• Observed dynamic interaction between out-of-equilibrium pumped spins and spin-momentum-locked flowing spins.
• Confirmed the perpendicular relationship between these spins and the generated charge current.
• Identified Sb as a promising material for spintronics due to its topological surface states.

Conclusions:

• Antimony films exhibit significant spin-momentum locking on their Rashba surface states.
• The inverse Rashba-Edelstein effect in Sb allows for efficient manipulation of charge currents.
• Sb nanostructures are suitable for developing low-power spintronic logic gates operating at microampere currents.