Switching on surface conduction in a topological insulator

Abstract

The protected surface conduction of topological insulators is in high demand for the next generation of electronic devices. What is needed to move forward are robust settings where topological surface currents can be controlled by simple means, ideally by the application of external stimuli. Surprisingly, this direction is only little explored. In this work we demonstrate that we can boost the surface conduction of a topological insulator by both light and electric field. This happens in a fully controlled way, and the additional Dirac carriers exhibit ultra-long lifetimes. We provide a comprehensive understanding, namely that carriers are injected from the bulk to the surface states across an intrinsic Schottky barrier. We expect this mechanism to be at play in a broad range of materials and experimental settings.

References in corpus (25)

• Topological Insulators
• Topological insulators and superconductors
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• Dirac materials
• Bulk Band Gap and Surface State Conduction Observed in Voltage-Tuned Crystals of the Topological Insulator Bi${}_2$Se${}_3$
• Observation of Dirac Holes and Electrons in a Topological Insulator
• Direct Evidence for the Dirac-Cone Topological Surface States in Ternary Chalcogenide TlBiSe2
• Single-Dirac-Cone topological surface states in TlBiSe2 class of Topological Insulators
• Theoretical Prediction of Topological Insulators in Thallium-based III-V-VI${}_2$ Ternary Chalcogenides
• Sn-doped Bi1.1Sb0.9Te2S, a bulk topological insulator with ideal properties
• Gigantic surface life-time of an intrinsic topological insulator revealed via time-resolved (pump-probe) ARPES
• Observations of two-dimensional quantum oscillations and ambipolar transport in the topological insulator Bi2Se3 achieved by Cd doping
• Time-resolved photoemission apparatus achieving sub-20-meV energy resolution and high stability
• Imaging emergent heavy Dirac fermions of a topological Kondo insulator
• Revealing puddles of electrons and holes in compensated topological insulators
• Persistent Optical Gating of a Topological Insulator
• Response of the topological surface state to surface disorder in TlBiSe${}_2$
• Surface Shubnikov-de Hass oscillations and non-zero Berry phases of the topological hole conduction in Tl${}_{1-x}$Bi${}_{1+x}$Se${}_2$
• Trigger of the ubiquitous surface band bending in 3D topological insulators
• Materials analysis and focused ion beam nanofabrication of topological insulator Bi2Se3
• Realization of bulk insulating property and carrier manipulation in reversible spin current regime of the ideal topological insulator TlBiSe2
• Role of surface termination in realizing well-isolated topological surface states within the bulk band gap in TlBiSe${}_2$ and TlBiTe${}_2$
• Robust scheme for magnetotransport analysis in topological insulators
• Reversible Engineering of Topological Insulator Surface State Conductivity through Optical Excitation
• Erasable superconductivity in topological insulator Bi2Se3 induced by voltage pulse