Stable topological insulators achieved using high energy electron beams

Abstract

Topological insulators are transformative quantum solids with immune-to-disorder metallic surface states having Dirac band structure. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift ($\sim 2.5$ MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap, and reach the charge neutrality point (CNP). Controlling the beam fluence we tune bulk conductivity from \textit{p}- (hole-like) to \textit{n}-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional (2D) character on the order of ten conductance quanta $G_0=e^2/h$, and reveals, both in Bi${}_2$Te${}_3$ and Bi${}_2$Se${}_3$, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size.

Main manuscript - 12 pages, 4 figures; Supplementary file - 15 pages, 11 figures, 1 Table, 4 Notes

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Cited by in corpus (7)

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• Tuning the Parity Mixing of Singlet-Septet Pairing in a Half-Heusler Superconductor
• Spin memory of the topological material under strong disorder
• Topological surface currents accessed through reversible hydrogenation of the three-dimensional bulk
• Fermi level dependence of magnetism and magnetotransport in the magnetic topological insulators Bi${}_2$Te${}_3$ and BiSbTe${}_3$ containing self-organized MnBi${}_2$Te${}_4$ septuple layers
• Time-Energy Uncertainty Limit for spin-related wavepacket evolution
• Self-organization mechanism in Bridgman-grown MnBi2Te4/(Bi2Te3)n: influence on layer sequence and magnetic properties