Quantum oscillations and optical conductivity in Rashba spin-splitting BiTeI

TL;DR

This study observes quantum oscillations in BiTeI, revealing a highly two-dimensional Fermi surface and Rashba spin-splitting, combining magnetoresistance and optical spectroscopy to deepen understanding of its electronic structure.

Contribution

It provides the first clear observation of Shubnikov-de Haas oscillations in BiTeI and links these to Rashba spin-splitting using combined experimental techniques.

Findings

Detected a single quantum oscillation frequency at 284.3 T.

Fermi surface is highly two-dimensional based on tilt suppression.

Optical spectroscopy supports bulk Rashba splitting with momentum 0.046 Å^{-1}.

Abstract

We report the observation of Shubnikov-de Haas (SdH) oscillations in single crystals of the Rashba spin-splitting compound BiTeI, from both longitudinal ($R_{xx}(B)$) and Hall ($R_{xy}(B)$) magnetoresistance. Under magnetic field up to 65 T, we resolved unambiguously only one frequency $F = 284.3\pm 1.3$ T, corresponding to a Fermi momentum $k_{F} = 0.093\pm 0.002$\AA$^{-1}$.The amplitude of oscillations is strongly suppressed by tilting magnetic field, suggesting a highly two-dimensional Fermi surface. Combining with optical spectroscopy, we show that quantum oscillations may be consistent with a bulk conduction band having a Rashba splitting momentum $k_{R}=0.046\pm$\AA$^{-1}$.