Related papers: Time delays from one-photon transitions in the con…
Photoionization is a key step in many attosecond processes. Accurately determining the photoionization time delay is critical to understanding electron dynamics during and after ionization and can guide future efforts to manipulate electron…
We develop a first-principles simulation method for attosecond time-resolved photoelectron spectroscopy. This method enables us to directly simulate the whole experimental processes, including excitation, emission and detection on equal…
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…
Measuring the delay for an electron to emerge from different states is one of the major achievements of attosecond science. This delay can have two origins - the electron wave packet is reshaped during departure by the electrostatic field…
Photoionization from energetically distinct electronic states may have a relative time delay of tens of attoseconds. Here we demonstrate that pulses of optical vortices allow measuring such attoseconds delays from magnetic sublevels, even…
To measure and control the electron motion in atoms and molecules by the strong laser field on the attosecond time scale is one of the research frontiers of atomic and molecular photophysics. It involves many new phenomena and processes and…
Attosecond pulses can be used to initiate and control electron dynamics on a sub-femtosecond time scale. The first step in this process occurs when an atom absorbs an ultraviolet photon leading to the formation of an attosecond electron…
Resonances leave prominent signatures in atomic and molecular ionization triggered by the absorption of single or multiple photons. These signatures reveal various aspects of the ionization process, characterizing both the initial and final…
We illustrate how attosecond light pulses can be used to directly mapping out the time-dependence of the correlated motion of two excited atomic electrons, discuss how the two-electron correlations manifest themselves in realistic…
We investigate attosecond time delays in the emission of photoelectrons using a hierarchy of models of the $CO_2$ molecule including the strong field approximation, Coulomb-scattering, short-range parts of the molecular potential, Hartree…
How quanta of energy and charge are transported on both atomic spatial and ultrafast time scales is at the heart of modern technology. Recent progress in ultrafast spectroscopy has allowed us to directly study the dynamical response of an…
We describe a numerical method that simulates the interaction of the helium atom with sequences of femtosecond and attosecond light pulses. The method, which is based on the close-coupling expansion of the electronic configuration space in…
Electron dynamics in water are of fundamental importance for a broad range of phenomena, but their real-time study faces numerous conceptual and methodological challenges. Here, we introduce attosecond size-resolved cluster spectroscopy and…
The response time of the electron to light in photoemission is difficult to define and measure. Tunneling ionization of atoms, a strong-laser-induced photoemission process, provides a semiclassical case for visiting the problem. Here, we…
Tunneling of a particle through a potential barrier is a fundamental physical process and a major thought-provoking outcome of quantum physics. It is at the basis of multiple scientific and technological advances and strongly influences…
Using extreme-ultraviolet attosecond-pulse-trains, we investigate the photoionization dynamics of a Helium atom in the presence of moderately-strong (~10^12 W/cm^2) femtosecond laser pulses. The electronic structure of a laser-dressed atom…
We study resonant two-photon ionization of helium atoms via the $1s3p$, $1s4p$ and $1s5p^1$P$_1$ states using the 15$^\mathrm{th}$ harmonic of a titanium-sapphire laser for the excitation and a weak fraction of the laser field for the…
Phase-shift differences and amplitude ratios of the outgoing $s$ and $d$ continuum wave packets generated by two-photon ionization of helium atoms are determined from the photoelectron angular distributions obtained using velocity map…
Focused laser fields with textured polarization on a sub-wavelength scale allow extracting information on electronic processes which are not directly accessible by homogeneous fields. Here, we consider photoionization in radially and…
The concerted motion of two or more bound electrons governs atomic and molecular non-equilibrium processes and chemical reactions. It is thus a long-standing scientific dream to measure the dynamics of two bound correlated electrons in the…