Spin-to-Charge Conversion in Ag/Bi Bilayer Revisited.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Spin-to-charge conversion is crucial for spintronic devices.
• The Ag/Bi interface is a candidate for studying spin-charge coupling phenomena.
• Distinguishing between the inverse spin Hall effect (ISHE) and inverse Rashba-Eldestein effect (IREE) is challenging.

Purpose of the Study:

• To elucidate the spin-to-charge conversion mechanism at the Ag/Bi interface.
• To differentiate between the ISHE and IREE in this system.
• To provide a reliable method for identifying spin-charge conversion mechanisms in Rashba systems.

Main Methods:

• Fabrication of a device allowing selective spin current injection from Ag or Bi sides.
• Measurement of generated charge voltages from counterpropagating spin currents.
• Utilizing femtosecond laser to generate spin-current-induced terahertz (THz) signals.

Main Results:

• Charge voltages from spin currents injected from opposite sides exhibited opposite signs.
• This sign difference is consistent with the ISHE, not the IREE.
• THz emission measurements showed no evidence supporting the IREE.

Conclusions:

• The dominant spin-to-charge conversion mechanism at the Ag/Bi interface is the ISHE.
• The study presents a clear method to identify spin-charge conversion mechanisms in Rashba systems.
• Findings advance the understanding of spin transport phenomena in metallic bilayers.