Dielectric response effects in attosecond time-resolved streaked photoelectron spectra of metal surfaces

Secondary electron cascade in attosecond photoelectron spectroscopy from metals

Attosecond spectroscopy is currently restricted to photon energies around 100 eV. We show that under these conditions, electron-electron scatterings, as the photoelectrons leave the metal give rise to a tail of secondary electrons with lower energies and hence a significant background. We develop an analytical model based on an approximate solution to Boltzmann's transport equation, to account for the amount and energy distribution of these secondary electrons. Our theory is in good agreement with the electron spectrum found in a recent attosecond streaking experiment. To suppress the backgrou…

Streaking and Wigner time delays in photoemission from atoms and surfaces

Streaked photoemission metrology allows the observation of an apparent relative time delay between the detection of photoelectrons from different initial electronic states. This relative delay is obtained by recording the photoelectron yield as a function of the delay between an ionizing ultrashort extended ultraviolet (XUV) pulse and a streaking infrared (IR) pulse. Theoretically, photoemission delays can be defined based on i) the phase shift the photoelectron wavefunction accumulates during the release and propagation of the photoelectron (``Wigner delay") and, alternatively, ii) the streak…

Simulation of attosecond streaking of electrons emitted from a tungsten surface

First time-resolved photoemission experiments employing attosecond streaking of electrons emitted by an XUV pump pulse and probed by a few-cycle NIR pulse found a time delay of about 100 attoseconds between photoelectrons from the conduction band and those from the 4f core level of tungsten. We present a microscopic simulation of the emission time and energy spectra employing a classical transport theory. Emission spectra and streaking images are well reproduced. Different contributions to the delayed emission of core electrons are identified: larger emission depth, slowing down by inelastic s…

固态光电发射中的大差分阿秒延迟

Large differential attosecond delays in solid state photoemission

本研究通过测量固态光电发射中的差分阿秒延迟，揭示了自旋轨道分裂态间电子动力学的复杂行为。

Attosecond spectroscopy of solids: streaking phase shift due to lattice scattering

Theory of laser-assisted photoemission from solids is developed for a numerically exactly solvable model with full inclusion of band structure effects. The strong lattice scattering in the vicinity of band gaps leads to a distortion and a temporal shift of the streaking spectrogram of the order of 100 as. The effect is explained in terms of Bloch electron dynamics and is shown to remain large for an arbitrarily small photoelectron mean free path. The implications for the streaking experiment on W(110) [A. L. Cavalieri et al., Nature (London) {\bf 449}, 1029 (2007)]

Attosecond Dynamics in Liquids

Attosecond science is well developed for atoms and promising results have been obtained for molecules and solids. Here, we review the first steps in developing attosecond time-resolved measurements in liquids. These advances provide access to time-domain studies of electronic dynamics in the natural environment of chemical reactions and biological processes. We concentrate on two techniques that are representative of the two main branches of attosecond science: pump-probe measurements using attosecond pulses and high-harmonic spectroscopy (HHS). In the first part, we discuss attosecond photoel…