Related papers: Controlling ultrafast currents by the non-linear p…
High-harmonic generation is one of the most extreme nonlinear-optical processes observed to date. By focusing an intense laser pulse into a gas, the light-atom interaction that occurs during the process of ionising the atoms results in the…
We develop a theory of the nonlinear optical responses in superconducting systems in the presence of a dc supercurrent. The optical transitions between particle-hole pair bands across the superconducting gap are allowed in clean…
We study theoretically the interaction of ultrashort optical pulses with gapped graphene. Such strong pulse results in finite conduction band population and corresponding electric current both during and after the pulse. Since gapped…
A circularly polarized laser pulse can induce persistent intra-molecular currents by either exciting or ionizing molecules. These two cases are identified as electron currents and hole currents, respectively, and up to now they have been…
All-optical pump-probe detection of magnetization precession has been performed for ferromagnetic EuO thin films at 10 K. We demonstrate that the circularly-polarized light can be used to control the magnetization precession on an ultrafast…
It is now well established that a few femtosecond laser pulse will induce an ultrafast loss of moment in a magnetic material. Here we show that the opposite effect can also occur: an ultrafast increase in moment. Employing both…
The requirement for optical-electrical-optical conversion of signals in optical technologies is often one of the majors bottleneck in terms of speed and energy consumption. The use of dressed photons (also called polaritons), that allows…
Exotic magnetic textures emerging from the subtle interplay between thermodynamic and topological fluctuation have attracted intense interest due to their potential applications in spintronic devices. Recent advances in electron microscopy…
We study ultrafast ionization dynamics using orthogonally polarized two-color (OTC) laser pulses involving the resonant "first plus second" ($\omega+2\omega$) scheme. The scheme is illustrated by numerical simulations of the time-dependent…
Topological properties of a three-dimensional Dirac semimetal Cd3As2, protected by crystal rotation and time-reversal symmetry, can be tuned with the application of pressure. Ultrafast spectroscopy is a unique tool to investigate the…
Specific features of nonlinear interference processes at quantum transitions in near- and fully-resonant optically-dense Doppler-broadened medium are studied. The feasibility of overcoming of the fundamental limitation on a…
In this paper, we investigate coherent control of nonadiabatic dynamics at a conical intersection (CI) using engineered ultrafast laser pulses. Within a model vibronic system, we tailor pulse chirp and temporal profile and compute the…
Ultrafast photon-assisted tunneling is shown to lead to large nonlinear dynamic currents that can be used to generate dc rectified current as well as higher order harmonic response from a metasurface-coupled tunnel diode. This artificial…
We generate high-order harmonics in gaseous medium with tunable photon energy using time domain interferometry of double pulses in a non-collinear generation geometry. The method is based on the fact that the generated harmonics inherit…
Ultrafast lasers are becoming increasingly widespread in science and industry alike. Fiber-based ultrafast laser sources are especially attractive because of their compactness, alignment-free setups, and potentially low costs. However,…
Optical control of crystal structures is a promising route to change physical properties including topological nature of a targeting material. Time-resolved X-ray diffraction measurements using the X-ray free-electron laser are performed to…
The propagation of light-pulse with negative group-velocity in a nonlinear medium is studied theoretically. We show that the necessary conditions for these effects to be observable are realized in a three-level $\Lambda$-system interacting…
We investigate spontaneous radiative processes in a driven polar two-level system whose interaction with the laser field is dominated by broken inversion symmetry rather than by the usual transition dipole coupling. Using a polaron…
Progress in optical techniques has made precision control of the phase profile in optical pulses common and accessible in scientific laboratories. Carefully shaping the field profile of a laser pulse can be used to master the dynamics of…
We study the effect of laser driving on a minimal model for a hexagonal two-dimensional material with broken inversion symmetry. Through the application of circularly polarised light and coupling to a thermal free electron bath, the system…