Free-electron lasers and high-harmonic-generation table-top systems are new sources of
extreme-ultraviolet to hard X-ray photons, providing ultrashort pulses that are intense …

Attosecond science requires a substantial rethinking of how to make measurements on very
short timescales; how to acquire the necessary equipment, technology, and personnel; and …

In the Bohr model of the atom, the nominal orbiting period for a 1s electron in the hydrogen
atom is 150 as (1 as= 10− 18 s). Attosecond light pulses are thus in principle short enough to …

Extending nonlinear spectroscopic techniques into the x-ray domain promises unique
insight into photoexcited charge dynamics, which are of fundamental and applied interest …

Coherence can drive wave-like motion of electrons and nuclei in photoexcited systems,
which can yield fast and efficient ways to exert materials' functionalities beyond the …

There is great interest in developing fully coherent multidimensional X-ray/extreme
ultraviolet (XUV) spectroscopic techniques because of their capability for achieving atomic …

We investigate the ultrafast electron dynamics of a model of a wide-band-gap material with
inner, valence, and conduction bands excited by an intense few-femtosecond pump and …

Since their introduction, all-optical spectroscopy techniques based on attosecond radiation
have gained the attention of the scientific community because of their energy and time …

We theoretically propose a multidimensional high-harmonic echo spectroscopy technique
which utilizes strong optical fields to resolve coherent electron dynamics spanning an …

The helium atom, with one nucleus and two electrons, is a prototypical system to study
quantum many-body dynamics. Doubly excited states, or quantum states in which both …