Spectroscopic evidence for a new type of surface resonance at noble metal surfaces

TL;DR

This study reveals a previously unknown surface resonance on the (110) surface of silver, characterized by a large bulk component, identified through threshold photoemission and confirmed by calculations.

Contribution

It reports the discovery of a new surface resonance with significant bulk character on noble metal surfaces, using advanced spectroscopic techniques.

Findings

Identification of a new surface resonance on Ag(110)

Characterization of the resonance's bulk-like properties

Confirmation via photocurrent calculations

Abstract

We investigate the surface- and bulk-like properties of the pristine (110)-surface of silver using threshold photoemission by excitation with light of 5.9 eV. Using a momentum microscope, we identified two distinct transitions along the $\overline{\Gamma}\,\overline{\textrm{Y}}$-direction of the crystal. The first one is a so far unknown surface resonance for the (110) noble metal surface, exhibiting an exceptionally large bulk character, that has so far been elusive in surface sensitive experiments. The second one stems from the well known bulk-like Mahan cone oriented along the $\Gamma L$-direction inside the crystal but projected onto the (110)-surface cut. The existence of the new state is confirmed by photocurrent calculations and its character analyzed.