Evidence of vectorial photoelectric effect on Copper

TL;DR

This paper investigates the vectorial photoelectric effect in copper, demonstrating QE enhancement in p polarization that cannot be explained by optical absorption, and proposes a non-local conductivity tensor explanation.

Contribution

It provides experimental evidence of the vectorial photoelectric effect on copper and introduces a theoretical explanation involving non-local conductivity tensor.

Findings

Maximum QE of ~4×10^{-4} in p polarization at 65° incidence

QE enhancement in p polarization not explained by optical absorption

Proposed explanation involves non-local conductivity tensor

Abstract

Quantum Efficiency (QE) measurements of single photon photoemission from a Cu(111) single crystal and a Cu polycrystal photocathodes, irradiated by 150 fs-6.28 eV laser pulses, are reported over a broad range of incidence angle, both in s and p polarizations. The maximum QE (\simeq 4\times10^{-4}) for polycrystalline Cu is obtained in p polarization at an angle of incidence {\theta} = 65deg. We observe a QE enhancement in p polarization which can not be explained in terms of optical absorption, a phenomenon known as vectorial photoelectric effect. Issues concerning surface roughness and symmetry considerations are addressed. An explanation in terms of non local conductivity tensor is proposed.