Experimental evidence and control of the bulk-mediated intersurface coupling in topological insulator Bi2Te2Se nanoribbons

Abstract

Nearly a decade after the discovery of topological insulators (TIs), the important task of identifying and characterizing their topological surface states through electrical transport experiments remains incomplete. The interpretation of these experiments is made difficult by the presence of residual bulk carriers and their coupling to surface states, which is not yet well understood. In this work, we present the first evidence for the existence and control of bulk-surface coupling in Bi2Te2Se nanoribbons, which are promising platforms for future TI-based devices. Our magnetoresistance measurements reveal that the number of coherent channels contributing to quantum interference in the nanoribbons changes abruptly when the film thickness exceeds the bulk phase relaxation length. We interpret this observation as an evidence for bulk-mediated coupling between metallic states located on opposite surfaces. This hypothesis is supported by additional magnetoresistance measurements conducted under a set of gate voltages and in a parallel magnetic field, the latter of which alters the intersurface coupling in a controllable way.

References in corpus (10)

• Topological Field Theory of Time-Reversal Invariant Insulators
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Impurity effect on weak anti-localization in the topological insulator Bi2Te3
• Emergent quantum confinement at topological insulator surfaces
• Tunable Surface Conductivity in Bi2Se3 Revealed in Diffusive Electron Transport
• Weak Localization and Antilocalization in Topological Insulator Thin Films with Coherent Bulk-Surface Coupling
• Emergence of decoupled surface transport channels in bulk insulating Bi2Se3 thin films
• Two-dimensional universal conductance fluctuations and the electron-phonon interaction of topological surface states in Bi2Te2Se nanoribbons
• Surface-to-bulk scattering in topological insulator films

Cited by in corpus (5)

• Signature of surface state coupling in thin films of the topological Kondo insulator SmB${}_6$ from anisotropic magnetoresistance
• Transport in topological insulators with bulk-surface coupling: Interference corrections and conductance fluctuations
• Evidence of decoupling of surface and bulk states in Dirac semimetal $C{d}_{3}A{s}_2$
• Universal Conductance Fluctuations of Topological Insulators
• Gate-Tunable Spin-to-Charge Conversion in Topological Insulator-Magnetic Insulator Heterostructures at Room Temperature