Optical evidence of surface state suppression in Bi based topological insulators

Abstract

A key challenge in condensed matter research is the optimization of topological insulator (TI) compounds for the study and future application of their unique surface states. Truly insulating bulk states would allow the exploitation of predicted surface state properties, such as protection from backscattering, dissipationless spin-polarized currents, and the emergence of novel particles. Towards this end, major progress was recently made with the introduction of highly resistive Bi${}_2$Te${}_2$Se, in which surface state conductance and quantum oscillations are observed at low temperatures. Nevertheless, an unresolved and pivotal question remains: while room temperature ARPES studies reveal clear evidence of TI surface states, their observation in transport experiments is limited to low temperatures. A better understanding of this surface state suppression at elevated temperatures is of fundamental interest, and crucial for pushing the boundary of device applications towards room-temperature operation. In this work, we simultaneously measure TI bulk and surface states via temperature dependent optical spectroscopy, in conjunction with transport and ARPES measurements. We find evidence of coherent surface state transport at low temperatures, and propose that phonon mediated coupling between bulk and surface states suppresses surface conductance as temperature rises.

13 pages, 10 figures

References in corpus (15)

• Carrier transport in 2D graphene layers
• A self-consistent theory for graphene transport
• Observation of Dirac Holes and Electrons in a Topological Insulator
• Surface State Transport and Ambipolar Electric Field Effect in Bi2Se3 Nanodevices
• Sum Rules for the Optical and Hall Conductivity in Graphene
• Topological Surface States and Dirac point tuning in ternary Bi2Te2Se class of topological insulators
• Optical properties of Bi2Te2Se at ambient and high pressure
• Growth of High-Mobility Bi2Te2Se Nanoplatelets on hBN Sheets by van der Waals Epitaxy
• Phonon-induced topological transitions and crossovers in Dirac materials
• Optical Properties of III-Mn-V Ferromagnetic Semiconductors
• Intrinsic Electron-Phonon Resistivity in Bi2Se3 in the Topological Regime
• Electron-phonon scattering in topological insulators
• f-Sum Rule and Unconventional Spectral Weight Transfer in Graphene
• Dirac cone shift of a passivated topological Bi2Se3 interface state
• Model-Independent Sum Rule Analysis Based on Limited-Range Spectral Data

Cited by in corpus (12)

• Evidence of surface transport and weak anti-localization in single crystal of Bi2Te2Se topological insulator
• Temperature-induced topological phase transitions: promoted vs. suppressed non-trivial topology
• Observation of Chiral Surface Excitons in a Topological Insulator Bi${}_2$Se${}_3$
• Surface-to-bulk scattering in topological insulator films
• Gate-Variable Mid-Infrared Optical Transitions in a $(B{i}_{1-x}S{b}_x{)}_{2}T{e}_3$ Topological Insulator
• Infrared electrodynamics and ferromagnetism in the topological semiconductors Bi${}_2$Te${}_3$ and Mn-doped Bi${}_2$Te${}_3$
• Van Hove Singularity Arising from Mexican-Hat-Shaped Inverted Bands in the Topological Insulator Sn-doped Bi${}_{1.1}$Sb${}_{0.9}$Te${}_2$S
• Temperature dependence of the topological phase transition of BiTeI from first principles
• Doping-dependent charge dynamics in CuxBi2Se3
• Optical investigation of thermoelectric topological crystalline insulator Pb${}_{0.77}$Sn${}_{0.23}$Se
• Evidence for a New Excitation at the Interface Between a High-Tc Superconductor and a Topological Insulator
• Fano q-reversal in topological insulator Bi2Se3