Direct evidence of spin-split one-dimensional metallic surface state on Si(557)-Au

TL;DR

This study provides direct experimental evidence of a spin-split one-dimensional metallic surface state on Si(557)-Au, revealing Rashba-type spin polarization and large out-of-plane spin components through advanced spectroscopic techniques and theoretical calculations.

Contribution

It presents the first direct evidence of spin-split surface states on Si(557)-Au, combining high-resolution spectroscopy with first principles calculations to characterize their spin properties.

Findings

Observation of double parabolic energy dispersions along Au chains.

Reversal of spin polarization at the time-reversal symmetry point.

Detection of large out-of-plane spin polarization.

Abstract

We report unprecedented evidence of a spin split one-dimensional metallic surface state for the system of Si(557)-Au obtained by means of high-resolution spin- and angle-resolved photoelectron spectroscopy combined with first principles calculations. The surface state shows double parabolic energy dispersions along the Au chain structure together with a reversal of the spin polarization with respect to the time-reversal symmetry point as is characteristic from the Rashba effect. Moreover, we have observed a considerably large out-of-plane spin polarization which we attribute to the highly anisotropic wave function of the gold chains.