High-temperature quantum oscillations of the Hall resistance in bulk Bi$_2$Se$_3$

TL;DR

This study reports high-temperature quantum oscillations of the Hall resistance in bulk Bi$_2$Se$_3$, revealing coexistence of topological surface states and layered 2D transport, with implications for quantum material understanding.

Contribution

It demonstrates quantum oscillations of the Hall resistance up to 50 K in bulk Bi$_2$Se$_3$ and identifies coexistence of 3D and 2D transport contributions.

Findings

Quantum oscillations observed up to 50 K.

Coexistence of topological surface states and layered 2D transport.

Angular and temperature dependence confirm 3D and 2D contributions.

Abstract

Helically spin-polarized Dirac fermions (HSDF) in protected topological surface states (TSS) are of high interest as a new state of quantum matter. In three-dimensional (3D) materials with TSS, electronic bulk states often mask the transport properties of HSDF. Recently, the high-field Hall resistance and low-field magnetoresistance indicate that the TSS may coexist with a layered two-dimensional electronic system (2DES). Here, we demonstrate quantum oscillations of the Hall resistance at temperatures up to 50 K in bulk Bi$_2$Se$_3$ with a high electron density $n$ of about $2\!\cdot\!10^{19}$ cm$^{-3}$. From the angular and temperature dependence of the Hall resistance and the Shubnikov-de Haas oscillations we identify 3D and 2D contributions to transport. Angular resolved photoemission spectroscopy proves the existence of TSS. We present a model for Bi$_2$Se$_3$ and suggest that the coexistence of TSS and 2D layered transport stabilizes the quantum oscillations of the Hall resistance.