High-Field Shubnikov-de Haas Oscillations in the Topological Insulator Bi$_2$Te$_2$Se

TL;DR

This study measures high-field surface Shubnikov-de Haas oscillations in Bi$_2$Te$_2$Se, confirming Dirac spectrum characteristics and revealing a small surface g-factor in topological insulators.

Contribution

It provides the first detailed high-field SdH oscillation data in Bi$_2$Te$_2$Se, confirming Dirac fermion behavior and small g-factor on the surface.

Findings

Observation of ~15 surface SdH oscillations up to 45 Tesla

Confirmation of the half-integer shift consistent with Dirac spectrum

Evidence of a very small surface Landé g-factor

Abstract

We report measurements of the surface Shubnikov de Haas oscillations (SdH) on crystals of the topological insulator Bi$_2$Te$_2$Se. In crystals with large bulk resistivity ($\sim$4 $\Omega$cm at 4 K), we observe $\sim$15 surface SdH oscillations (to the $n$ = 1 Landau Level) in magnetic fields $B$ up to 45 Tesla. Extrapolating to the limit $1/B\to 0$, we confirm the $\frac12$-shift expected from a Dirac spectrum. The results are consistent with a very small surface Lande $g$-factor.