Distinguishing bulk and surface electron-phonon coupling in the topological insulator Bi2Se3 using time-resolved photoemission spectroscopy

Abstract

We report time- and angle-resolved photoemission spectroscopy measurements on the topological insulator Bi2Se3. We observe oscillatory modulations of the electronic structure of both the bulk and surface states at a frequency of 2.23 THz due to coherent excitation of an A1g phonon mode. A distinct, additional frequency of 2.05 THz is observed in the surface state only. The lower phonon frequency at the surface is attributed to the termination of the crystal and thus reduction of interlayer van der Waals forces, which serve as restorative forces for out-of-plane lattice distortions. DFT calculations quantitatively reproduce the magnitude of the surface phonon softening. These results represent the first band-resolved evidence of the A1g phonon mode coupling to the surface state in a topological insulator.

References in corpus (14)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Bulk Fermi surface coexistence with Dirac surface state in Bi${}_2$Se${}_3$: a comparison of photoemission and Shubnikov-de Haas measurements
• Strong surface scattering in ultrahigh mobility Bi2Se3 topological insulator crystals
• Ultrafast Optical Excitation of a Persistent Surface-State Population in the Topological Insulator Bi2Se3
• Ultrafast surface carrier dynamics in the topological insulator Bi2Te3
• Electron-phonon Coupling on the Surface of the Topological Insulator Bi2Se3: Determined from Surface Phonon Dispersion Measurements
• Ultrafast carrier and phonon dynamics in Bi2Se3 crystals
• Spatially resolved femtosecond pump-probe study of topological insulator Bi2Se3
• Ultrafast photodoping and effective Fermi-Dirac distribution of the Dirac particles in Bi2Se3
• Fingerprints of Inelastic Transport at the Surface of the Topological Insulator Bi2Se3: Role of Electron-Phonon Coupling
• Principles of crystal growth of intermetallic and oxide compounds from molten solutions

Cited by in corpus (20)

• Angle-resolved photoemission spectroscopy and its application to topological materials
• Spin-Polarized Surface Resonances Accompanying Topological Surface State Formation
• Momentum resolved spin dynamics of bulk and surface excited states in the topological insulator $\mathrm{B}{\mathrm{i}}_2\mathrm{S}{\mathrm{e}}_3$
• Sub-picosecond spin dynamics of excited states in the topological insulator Bi${}_2$Te${}_3$
• Observation of Chiral Surface Excitons in a Topological Insulator Bi${}_2$Se${}_3$
• Mode-selective coupling of coherent phonons to the Bi2212 electronic band structure
• A time- and angle-resolved photoemission spectroscopy with probe photon energy up to 6.7 eV
• Polarization dependence of coherent phonon generation and detection in the 3D topological insulator Bi2Te3
• Thickness-Dependent Coherent Phonon Frequency in Ultrathin FeSe/SrTiO${}_3$ Films
• Surface Phonons in the Topological Insulators Bi2Se3 and Bi2Te3
• Time-resolved ARPES on cuprates: Tracking the low-energy electrodynamics in the time domain
• Ultrafast Switching from the Charge Density Wave Phase to a Metastable Metallic State in 1T-TiSe${}_2$
• Observation of antiphase coherent phonons in the warped Dirac cone of Bi${}_2$Te${}_3$
• Nanoscale Determination of the Mass Enhancement Factor in the Lightly-Doped Bulk Insulator Lead Selenide
• Electron-phonon correlations on spin texture of gapped helical Dirac Fermions
• Phase diagram and phonon-induced backscattering in topological insulator nanowires
• Comment on 'Unraveling Photoinduced Spin Dynamics in the Topological Insulator Bi2Se3'
• Phonon and defect mediated quantum anomalous Hall insulator to metal transition in magnetically doped topological insulators
• Ultrafast scattering dynamics of coherent phonons in Bi${}_{1-x}$Sb${}_x$ in the Weyl semimetal phase
• Ultrafast electron dynamics at the Dirac node of the topological insulator Sb${}_2$Te${}_3$