Magneto transport and first principle study of strong topological insulator gray Arsenic

TL;DR

This study synthesizes high-quality gray arsenic crystals, demonstrating their metallic behavior, large magneto-resistance, and topological surface states confirmed by first-principles calculations, highlighting potential topological insulator properties.

Contribution

First-principles calculations combined with experimental synthesis and characterization reveal topological surface states in gray arsenic, a novel topological insulator candidate.

Findings

High residual resistivity ratio indicates high metallicity.

Large magneto-resistance observed at low temperatures.

Presence of topological surface states confirmed by SDH oscillations and calculations.

Abstract

This article reports the synthesis of a single crystalline gray Arsenic (As) via the Bismuth flux method. The X-ray Diffraction (XRD) pattern revealed the single phase of the grown crystal, which crystallized in the rhombohedral structure with the space group R3m. The sharp XRD peaks observed on mechanically exfoliated thin flakes of the same ensured high crystallinity of the same with growth direction along the c-axis. The resistivity measurements illustrated its metallic nature throughout, right from 300K down to 2K. The measured residual resistivity ratio of the sample is 180, which endorses the high metallic nature of the as-synthesized As single crystal. The transverse magnetic field-dependent resistivity (RH) measurements elucidated huge magneto-resistance (MR) at 2K and 14Tesla transverse magnetic fields. Also seen are the SDH oscillations, indicating the presence of topological surface states. The non-trivial band topology and edge states in As are confirmed by first principle calculations.