Anomalous behavior in the phonon dispersion of the (001) surface of Bi${}_2$Te${}_3$ determined from helium atom-surface scattering measurements

Abstract

We employ inelastic helium atom-surface scattering to measure the low energy phonon dispersion along high-symmetry directions on the surface of the topological insulator Bi${}_2$Te${}_3$. Results indicate that one particular low-frequency branch experiences noticeable mode softening attributable to the interaction between Dirac fermion quasiparticles and phonons on the surface. This mode softening constitutes a renormalization of the real part of the phonon self-energy. We obtain the imaginary part, and hence lifetime information, via a Hilbert transform. In doing so we are able to calculate an average branch specific electron-phonon coupling constant $<{\lambda }_{\nu }>=1.44$.

11 pages, 11 figures

References in corpus (2)

• Topological Insulators with Inversion Symmetry
• Electron-phonon scattering in topological insulators

Cited by in corpus (10)

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• Nanoscale Surface Dynamics of Bi${}_2$Te${}_3$(111): Observation of a Prominent Surface Acoustic Wave and the Role of van der Waals Interactions
• Surface Phonons in the Topological Insulators Bi2Se3 and Bi2Te3
• Connecting electron and phonon spectroscopy data to consistently determine quasiparticle-phonon coupling on the surface of topological insulators
• Nanoscale Determination of the Mass Enhancement Factor in the Lightly-Doped Bulk Insulator Lead Selenide
• A Helium-Surface Interaction Potential of Bi${}_2$Te${}_3$(111) from Ultrahigh-Resolution Spin-Echo Measurements
• Electron-phonon Coupling and Kohn Anomaly due to the Floating 2D Electronic Bands on the Surface of ZrSiS
• The anomalous spin texture as the probe for interactions in $B{i}_{2-y}S{b}_{y}S{e}_{x}T{e}_{3-x}$