A density functional theory study of the electron-phonon coupling at the Mo(112) surface

Area of Science:

• Condensed matter physics
• Materials science
• Surface science

Background:

• Electron-phonon (e-p) coupling is crucial for understanding material properties.
• Surface electronic states exhibit unique behaviors compared to bulk states.
• Molybdenum (Mo) and its alloys are technologically important materials.

Purpose of the Study:

• Investigate the electron-phonon coupling strength for the surface bands of Mo(112).
• Determine the contribution of surface phonon modes to e-p coupling.
• Explain the observed broadening of electronic surface bands at the Fermi level.

Main Methods:

• Utilized density functional theory (DFT) calculations.
• Analyzed the phonon density of states and Eliashberg function.
• Calculated the mass enhancement factor and self-energy.

Main Results:

• Identified significant contributions from surface phonon modes to low-frequency phonon spectra.
• Observed enhanced e-p coupling at the Mo(112) surface.
• Calculated increased mass enhancement factor and imaginary part of the self-energy.

Conclusions:

• Enhanced e-p coupling at the Mo(112) surface is driven by surface phonon modes.
• The enhanced coupling, alongside anharmonic effects and scattering, explains the increased linewidth of surface electronic bands.
• Findings provide insights into surface electronic properties and scattering mechanisms relevant to materials science.