High-field Shubnikov–de Haas oscillations in the topological insulator Bi2Te2Se

Abstract

We report measurements of the surface Shubnikov de Haas oscillations (SdH) on crystals of the topological insulator Bi2Te2Se. In crystals with large bulk resistivity (∼4 Ωcm at 4 K), we observe ∼15 surface SdH oscillations (to the n = 1 Landau Level) in magnetic fields B up to 45 Tesla. Extrapolating to the limit 1/B → 0, we confirm the 1 2 -shift expected from a Dirac spectrum. The results are consistent with a very small surface Lande g-factor.

Quantum oscillations of the topological surface states in low carrier concentration crystals of Bi2−xSbxTe3Pan1, Никитин2, Wu3 et al. 2016Solid State Communications7100View full textAdd to dashboardCite

“…Clearly, these values differ from the value π expected for topological surface states. A Berry phase extracted in this way that deviates from π has been reported frequently in other SdH studies on the 3D TI family (Bi,Sb) 2 (Te,Se) 3 [11,12,26,33,27]. However, obtaining n x by linear extrapolation is not justified in all cases.…”

“…At the same time, it may give direct access to the topological nature of the surface states via the geometric phase (Berry phase) [24,25] of the quantum oscillations. Therefore, the SdH effect in TIs has received ample attention in the literature, notably through experiments carried out on bulk crystals of Bi 2 Te 3 , Bi 2 Se 3 and Bi 2 Te 2 Se [12,11,26,27,28]. In addition, the SdH effect was reported for nonstochiometric BSTS (x, y)=(0.50,1.3) bulk crystals [29] and nanoflakes [30].…”

Topological Insulator Materials

“…The former can be done by looking at the sample-size dependence of the conductance, 108,[140][141][142] and the latter may be accomplished by elucidating the Berry phase in the quantum oscillations from the surface state. 103,104,108,[170][171][172][173] (Detailed discussions on the identification of the Berry phase will be given in Sect. 8.3.)…”

Topological surface states and Dirac point tuning in ternary topological insulators

“…Electronic structure studies on Bi 2 Te 2 Se is of interest since this compound seems to have the highest bulk resistivity among all known topological insulators. 25,26 Bi 2 Te 2 Se is a distinct line compound in the phase diagram known as "Kawazulite" 22,25,39 (as opposed to a random mixture of Bi 2 Se 3 and Bi 2 Te 3 ). The interpretation of any surface transport measurements will rely on key band structure properties and parameters, such as Fermi velocity, Fermi momentum, etc., which have yet to be reported on Bi 2 Te 2 Se.…”