Attosecond time-resolved streaked photoemission from Mg--covered W(110) surfaces

We formulate a quantum-mechanical model [1,2] for infrared-streaked photoelectron emission by an ultrashort extreme ultraviolet pulse from adsorbate--covered metal surfaces. Applying this numerical model to ultrathin Mg adsorbates on W(110) substrates, we analyze streaked photoelectron spectra and attosecond streaking time delays [3] for photoemission from the Mg/W(110) conduction band and Mg(2p) and W(4f) core levels. Based on this analysis, we propose the use of attosecond streaking spectroscopy on adsorbate--covered surfaces with variable adsorbate thickness as a method for investigating (a) electron transport in condensed-matter systems and (b) metal--adsorbate--interface properties at subatomic length and time scales. Our calculated streaked photoemission spectra and time delays agree with recently obtained experimental data.\\[4pt] [1] Q. Liao and U. Thumm, Phys. Rev. Lett. 112, 023602 (2014).\\[0pt] [2] Q. Liao and U. Thumm, Phys. Rev. A 89, 033849 (2014).\\[0pt] [3] U. Thumm, Q, Liao, E. M. Bothschafter, F. S\"u{\ss}mann, M. F. Kling, and R. Kienberger, in: Handbook of Photonics 1: ``Attosecond physics,'' ed. D. L. Andrew, ISBN:978-1-118-22553-0, Chapter XIII: ``Attosecond streaking spectroscopy of atoms and solids'' (Wiley, January 2015).