Self-energy and lifetime of Shockley and image states on Cu(100) and Cu(111): Beyond the GW approximation of many-body theory

TL;DR

This paper presents advanced many-body calculations of the self-energy and lifetime of surface states on copper surfaces, incorporating exchange-correlation effects beyond the standard GW approximation using a GWΓ approach.

Contribution

It introduces a GWΓ method that includes short-range exchange-correlation effects in both the screened interaction and the self-energy expansion, surpassing traditional GW calculations.

Findings

More accurate self-energy and lifetime predictions for Cu surface states.

Inclusion of nonlocal exchange-correlation effects improves theoretical results.

Enhanced understanding of surface electronic states beyond GW approximation.

Abstract

We report many-body calculations of the self-energy and lifetime of Shockley and image states on the (100) and (111) surfaces of Cu that go beyond the $GW$ approximation of many-body theory. The self-energy is computed in the framework of the GW\Gamma approximation by including short-range exchange-correlation (XC) effects both in the screened interaction W (beyond the random-phase approximation) and in the expansion of the self-energy in terms of W (beyond the GW approximation). Exchange-correlation effects are described within time-dependent density-functional theory from the knowledge of an adiabatic nonlocal XC kernel that goes beyond the local-density approximation.