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.
@article{arxiv.1201.3046,
title = {Evidence of vectorial photoelectric effect on Copper},
author = {Emanuele Pedersoli and Francesco Banfi and Barbara Ressel and Stefania Pagliara and Claudio Giannetti and Gianluca Galimberti and Steve Lidia and John Corlett and Gabriele Ferrini and Fulvio Parmigiani},
journal= {arXiv preprint arXiv:1201.3046},
year = {2012}
}