Orbital-Driven Rashba Effect in a Binary Honeycomb Monolayer AgTe.

Area of Science:

• Condensed Matter Physics
• Spintronics
• Surface Science

Background:

• The Rashba effect, crucial for spintronics, describes spin splitting in electron systems.
• A proposed microscopic origin involves orbital angular momentum (OAM) in Bloch wave functions.

Purpose of the Study:

• To provide experimental evidence for the OAM-based origin of the Rashba effect.
• To investigate the relationship between OAM and spin splitting in AgTe/Ag(111).

Main Methods:

• Angle-resolved photoemission spectroscopy (ARPES)
• Two-photon photoemission spectroscopy
• Quantitative low-energy electron diffraction (LEED)
• First-principles calculations

Main Results:

• Detailed structural parameters and stacking of the AgTe overlayer were determined with picometer precision.
• ARPES and calculations unequivocally linked the presence/absence of Rashba spin splittings to OAM in different AgTe bands.
• Experimental evidence supports the OAM-based origin of the Rashba effect.

Conclusions:

• The study confirms the microscopic origin of the Rashba effect is tied to orbital angular momentum.
• This finding advances the understanding of spin-orbit coupling in two-dimensional materials.
• The results have implications for designing novel spintronic devices.