Energy-momentum mapping of d-derived Au(111) states in a thin film

TL;DR

This study demonstrates how quantum well states in Au(111) thin films can be used to map and analyze the bulk electronic structure, revealing band edges, surface states, and spin-splittings with high precision.

Contribution

It introduces a method using angle-resolved photoemission spectroscopy of thin films to accurately determine bulk band parameters and surface state characteristics.

Findings

Bulk band edges confirmed by quantum well states

Identification of d-like surface states with large spin-splittings

Agreement of critical point positions with previous data

Abstract

The quantum well states of a film can be used to sample the electronic structure of the parent bulk material and determine its band parameters. We highlight the benefits of two-dimensional film band mapping, with respect to complex bulk analysis, in an angle-resolved photoemission spectroscopy study of the 5d states of Au(111). Discrete 5d-derived quantum well states of various orbital characters form in Au(111) films and span the width of the corresponding bulk bands. For sufficiently thick films, the dispersion of these states samples the bulk band edges, as confirmed by first-principles calculations, thus providing the positions of the critical points of bulk Au in agreement with previously determined values. In turn, this analysis identifies several d-like surface states and resonances with large spin-splittings that originate from the strong spin-orbit coupling of the Au 5d atomic levels.