Time-resolved photoelectron spectroscopy of Ag(111) and Au(111) surfaces

Upon illumination of transition metal surfaces with an XUV pulse train and a time-delayed phase-coherent IR pulse, recent experiments [1-3] have applied the RABBITT (reconstruction of attosecond beating by interference of two-photon transitions) technique to provide time-resolved information about the photoemission processes on surfaces. We simulated RABBITT spectra within a quantum-mechanical model, calculating the transition matrix element in the non-dipole velocity gauge between tight-binding initial and a modified-Volkov final states [4] and adjusting the substrate parameters to measured energy-resolved spectra for normal emission [5]. We compare our numerically modeled RABBITT spectra with experimental spectra obtained by Locher \textit{et al}. [1] for Ag(111) and Au(111) surfaces, accounting for electrons scattered through the substrate during the emission process by including a delay-independent photoelectron background [6]. [1] R. Locher \textit{et al.}, Optica \textbf{2}, 405 (2015). [2] Z. Tao \textit{et al.}, Science \textbf{353}, 62 (2016). [3] M. Lucchini \textit{et al.,} Phys. Rev. Lett. \textbf{115}, 137401 (2015). [4] M. J. Ambrosio and U. Thumm, Phys. Rev. A \textbf{96}, 051403 (2017). [5] F. Roth \textit{et al.} J. Electron. Spectrosc. Relat. Phenom., in press (2017). [6] M. J. Ambrosio and U. Thumm, in preparation.