Related papers: Ultrafast adsorbate excitation probed with sub-ps …
The electronic excitation occurring on adsorbates at ultrafast time scales from optical lasers that initiate surface chemical reactions is still an open question. Here, we report the ultrafast temporal evolution of X-ray absorption…
In recent years, ultrafast pump-probe spectroscopy has provided insightful information about nonequilibrium dynamics of excitations in materials. In a typical experiment of time-resolved x-ray absorption spectroscopy, the systems are…
Time-resolved vibrational spectroscopy constitutes an invaluable experimental tool for monitoring hot-carrier induced surface reactions. However, the absence of a full understanding on the precise microscopic mechanisms causing the…
Encoded in the transient x-ray absorption (XAS) and magnetic circular (MCD) response functions resides a wealth of information of the microscopic processes of ultrafast demagnetisation. Employing state of the art first principles dynamical…
Exploring and understanding ultrafast processes at the atomic level is a scientific challenge. Femtosecond X-ray Absorption Spectroscopy (XAS) is an essential experimental probing technic, as it can simultaneously reveal both electronic and…
A coherent vibrational wavepacket is launched and manipulated in the symmetric stretch (a$_1$) mode of CBr$_4$, by impulsive stimulated Raman scattering from non-resonant 400 nm laser pump pulses with various peak intensities on the order…
We report first ns-resolved absorption measurements of the ro-vibrational excitation of CO$_2$. The high temporal resolution of 8 ns is made possible by a fast detector (rise-time 5 ns), sensitive in the mid-infrared region. The resolution…
Core level binding energies and absorption edges are at the heart of many experimental techniques concerned with element-specific structure, electronic structure, chemical reactivity, elementary excitations and magnetism. X-ray…
Standard optical pump-probe methods analyze a system's temporal response to a laser pulse within sub-femtoseconds to several nanoseconds, constrained by the optical delay line's length. While resistance is a sensitive detector in various…
Recent seminal experiments have utilized time-resolved X-ray absorption spectroscopy (XAS) to investigate the ultrafast photo-induced renormalization of the electron interaction (''Hubbard $U$'') in Mott and charge transfer insulators. In…
Time-dependent and constituent-specific spectral changes in soft near edge X-ray spectroscopy (XAS) of an [Fe/MgO]$_8$ metal/insulator heterostructure upon laser excitation are analyzed at the O K-edge with picosecond time resolution. The…
X-ray absorption spectroscopy (XAS) is a powerful and well established technique with sensitivity to elemental and chemical composition. Despite these advantages, its implementation has not kept pace with the development of ultrafast pulsed…
Copper (Cu), gold (Au) (111) crystals were illuminated with 120 fs pulses and probed by 600 fs X-ray pulses. Rocking curves were measured versus 267 nm (UV) pump- 0.154 nm probe delay time. Curve width broadening, peak diffracted intensity…
In time-resolved pump-probe vibrational spectroscopy the internal stretch mode of polar molecules is utilized as a key observable to characterize the ultrafast dynamics of adsorbates on surfaces. The adsorbates non-adiabatic intermode…
Operando X-ray absorption spectroscopy (XAS) can probe the electrode-electrolyte interface with single-digit nanometer depth resolution and offers a wealth of insight into the evolution and Coulombic efficiency or degradation of prototype…
CO oxidation on Ru(0001) is a long-standing example of a reaction that, being thermally forbidden in ultra-high vacuum, can be activated by femtosecond laser pulses. In spite of its relevance, the precise dynamics of the photo-induced…
Laser-driven compact particle accelerators can provide ultrashort pulses of broadband X-rays, well suited for undertaking X-ray absorption spectroscopy measurements on a femtosecond timescale. Here the Extended X-ray Absorption Fine…
Ultrafast dynamics are generally investigated using stroboscopic pump-probe measurements, which characterize the sample properties for a single, specific time delay. These measurements are then repeated for a series of discrete time delays…
We investigate AC Stark-shifted resonances in argon with ultrashort near-infrared pulses. Using 30 fs pulses we observe periodic enhancements of the excitation yield in the intensity regions corresponding to the absorption of 13 and 14…
We present a new technique using a frequency comb laser and optical cavities for performing ultrafast transient absorption spectroscopy with improved sensitivity. Resonantly enhancing the probe pulses, we demonstrate a sensitivity of…