Related papers: Generation of Phonons with Angular Momentum During…
In the past decade, the advent of time-resolved spectroscopic tools has provided a new ground to explore fundamental interactions in solids and to disentangle degrees of freedom whose coupling leads to broad structures in the frequency…
We show that time-dependent density functional theory (TDDFT) is applicable to coherent optical phonon generation by intense laser pulses in solids. The two mechanisms invoked in phenomenological theories, namely impulsively stimulated…
Motivated by recent phonon spectroscopy experiments in the fractional quantum Hall regime we consider processes in which thermally excited magnetoroton excitations are scattered by low energy phonons. We show that such scattering processes…
We theoretically investigate pumping of phonons by the dynamics of a magnetic film into a non-magnetic contact. The enhanced damping due to the loss of energy and angular momentum shows interference patterns as a function of resonance…
The process of radiation induced electron capture by protons or deuterons producing new ultra low momentum neutrons and neutrinos may be theoretically described within the standard field theoretical model of electroweak interactions. For…
We study atomic autoionization processes in the time domain. With the emerging attosecond extreme vacuum ultraviolet and soft x-ray pulses, we first address how to characterize the time evolution of the decay of a discrete state into a…
A systematic investigation of spin injection behavior in Au/FM (FM = Fe and Ni) multilayers is performed using the superdiffusive spin transport theory. By exciting the nonmagnetic layer, the laser-induced hot electrons may transfer spin…
The dynamics of single laser-driven electrons and many particle systems with spin are investigated on the basis of a classical theory. We demonstrate that the spin forces can alter the electron dynamics in an ultra-relativistic laser field…
Ultrafast electron-phonon relaxation dynamics in graphene hides many distinct phenomena, such as hot phonon generation, dynamical Kohn anomalies, and phonon decoupling, yet still remains largely unexplored. Here, we unravel intricate…
Magnetic nanoparticles such as FePt in the L10-phase are the bedrock of our current data storage technology. As the grains become smaller to keep up with technological demands, the superparamagnetic limit calls for materials with higher…
Efforts to push the spatiotemporal imaging-resolution limits of femtosecond (fs) laser-driven ultrafast electron microscopes (UEMs) to the combined angstrom-fs range will benefit from stable sources capable of generating high bunch charges.…
We study the generation of coherent phonons in a superconductor by ultrafast optical pump pulses. The nonequilibrium dynamics of the coupled Bogoliubov quasiparticle-phonon system after excitation with the pump pulse is analyzed by means of…
Spin currents have been shown to play a key role in the ultrafast laser-driven demagnetization process in ferromagnetic thin films. Here, we show that an oscillating spin current can be generated in the film via the application of a…
Electron beams in scanning transmission electron microscopy (STEM) exert forces and torques on study samples, with magnitudes that allow the controlled manipulation of nanoparticles (a technique called electron tweezers). Related…
Terahertz (THz) lasers provide a new research perspective for spin electronics applications due to their sub-picosecond time resolution and non-thermal ultrafast demagnetization, but the interaction between spin, charge and lattice dynamics…
Ultrafast spectroscopy paved the way for probing transient states of matter produced through photoexcitation. Despite significant advances, the microscopic processes governing the formation of these states remain largely unknown. This study…
Nonlinear phononics holds the promise for controlling properties of quantum materials on the ultrashort timescale. Using nonequilibrium dynamical mean-field theory, we solve a model for the description of organic solids, where correlated…
High harmonic generation (HHG) is a widely explored process in solids, where intense lasers drive attosecond-to-femtosecond electron dynamics within bands, causing high-energy emission. While electrons and photons are considered the main…
In the field of chemistry, where nuclear motion has traditionally been a focal point, we now explore the ultra-rapid electronic motion spanning attoseconds to femtoseconds, demonstrating that it is equally integral and relevant to the…
We present a method for computing angle-resolved electron-energy-loss and gain spectroscopies for phonon and magnon excitations in transmission electron microscopy. Fractional scattering intensities are derived from the…