$L$-hole Pockets of the Palladium Fermi Surface Revealed by Positron Annihilation Spectroscopy

TL;DR

This study combines advanced theoretical methods and positron annihilation spectroscopy to reveal small $L$-hole pockets in palladium's Fermi surface, providing a clear experimental signature for their existence.

Contribution

It demonstrates that relativistic effects create $L$-hole pockets in palladium and that $2D$-ACAR measurements can experimentally confirm these features.

Findings

Relativistic corrections induce $L$-hole pockets in palladium.

$2D$-ACAR spectra clearly show these $L$-hole pockets.

The pockets are robust against electronic correlations.

Abstract

Using the combined Density Functional and Dynamical Mean Field theory we study relativistic corrections to the Fermi surface of palladium. We find indeed that relativistic corrections create a small hole pockets at the $L$-symmetry points. Furthermore we show that the computed two dimensional Angular Correlation of Electron Positron Annihilation Radiation (the so called $2D$-ACAR) clearly demonstrates the existence of these $L$-hole pockets, which remains robust against electronic correlations. A $2D$-ACAR experiment should therefore provide the "smoking-gun" proof for the existence of the $L$-hole pockets in the palladium Fermi surface.