Chiral Electronic Excitations in a Quasi-2D Rashba System BiTeI

TL;DR

This paper investigates chiral electronic excitations in the quasi-2D Rashba system BiTeI using polarization-resolved Raman spectroscopy, revealing new insights into Rashba parameters and band structure.

Contribution

It provides experimental detection of chiral excitations and compares measured Rashba parameters with theoretical calculations, advancing understanding of spin-polarized bands in BiTeI.

Findings

Detection of chiral excitations between opposite helicity states

Determination of Rashba parameters and band gaps from Raman spectra

Comparison of experimental parameters with DFT calculations

Abstract

The optical transitions between spin-polarized bands of the quasi-two dimensional Rashba system BiTeI are investigated using polarization resolved resonant Raman spectroscopy. We detect chiral excitations between states with opposite helicity and compare spectra to calculations within a three-band model. Using the resonant Raman excitation profile, we deduce the Rashba parameters and band gaps of the higher conduction bands near the Fermi level, and compare the parameters to values obtained by ab initio density function theory (DFT).