Quantifying many-body effects by high-resolution Fourier transform scanning tunneling spectroscopy

Area of Science:

• Surface Science
• Condensed Matter Physics
• Spectroscopy

Background:

• Many-body effects significantly influence material properties.
• Understanding electron interactions is crucial for novel electronic devices.
• Surface states exhibit unique electronic behaviors.

Purpose of the Study:

• To investigate many-body effects on the Ag(111) surface state using FT-STS.
• To identify the specific interactions responsible for observed band dispersion anomalies.
• To demonstrate FT-STS's capability in high-resolution self-energy extraction.

Main Methods:

• High-resolution Fourier transform scanning tunneling spectroscopy (FT-STS).
• Modeling experimental data with T-matrix formalism for impurity scattering.
• Analysis of electron-electron and electron-phonon interactions.

Main Results:

• Observed a kink in the surface electron band dispersion.
• Measured an increased quasiparticle lifetime near the Fermi energy.
• Confirmed electron-phonon interactions as the cause of dispersion deviations.
• Extracted Debye energy (ℏΩD=14±1 meV) and electron-phonon coupling strength (λ=0.13±0.02).

Conclusions:

• FT-STS accurately probes many-body effects on surfaces.
• The study quantifies electron-phonon coupling on Ag(111).
• FT-STS offers momentum and energy resolution comparable to ARPES for self-energy analysis.