Lifetimes of Shockley electrons and holes at the Cu(111) surface

TL;DR

This paper presents a theoretical analysis of the inelastic lifetimes of Shockley electrons and holes at the Cu(111) surface, emphasizing the importance of surface-state orbital shapes in decay processes.

Contribution

It introduces a detailed many-body theoretical approach using pseudopotential-based wave functions to accurately model Shockley state decay at the Cu(111) surface.

Findings

Lifetimes are highly sensitive to the shape of surface-state orbitals.

Comparison with experiments shows good agreement when orbital shapes are accurately modeled.

Surface-state decay mechanisms depend critically on the coupling between electrons and holes.

Abstract

A theoretical many-body analysis is presented of the electron-electron inelastic lifetimes of Shockley electrons and holes at the (111) surface of Cu. For a description of the decay of Shockley states both below and above the Fermi level, single-particle wave functions have been obtained by solving the Schr\"odinger equation with the use of an approximate one-dimensional pseudopotential fitted to reproduce the correct bulk energy bands and surface-state dispersion. A comparison with previous calculations and experiment indicates that inelastic lifetimes are very sensitive to the actual shape of the surface-state single-particle orbitals beyond the $\bar\Gamma$ (${\bf k}_\parallel=0$) point, which controls the coupling between the Shockley electrons and holes.