Related papers: Ultrafast Dynamics of Gallium Vacancy Charge State…
Ultrafast spectroscopies constitute a fundamental tool to investigate the dynamics of non-equilibrium many-body states in correlated materials. Two-pulses (pump-probe) experiments have shed new light on the interplay between high-energy…
We demonstrate an electric field-resolved approach for probing ultrafast dynamics of photoinjected charges in solids. Direct access to the electric field of few-cycle pulses enables us to measure a broadband response of a medium with…
We present a systematic investigation of native point defects and oxygen impurities in GaAs using hybrid functional calculations. Defects are characterized by their structural, electronic, and optical properties. Under thermodynamic…
Femtosecond coherent multidimensional spectroscopy is demonstrated for an ultracold gas. For this, a setup for phase modulation spectroscopy is used to probe the $3^2\mathrm{S}_{1/2} - 2^2\mathrm{P}_{1/2, 3/2}$ transition in an 800…
Disorder-induced ordering and unprecedentedly high radiation tolerance in $\gamma$-phase of gallium oxide is a recent spectacular discovery at the intersection of the fundamental physics and electronic applications. Importantly, by far,…
We present a multiscale atomistic-to-continuum method for ionic crystals with defects. Defects often play a central role in ionic and electronic solids, not only to limit reliability, but more importantly to enable the functionalities that…
The last decade has witnessed a rapid advancement in laser technology, enabling the direct monitoring and control of electronic motion on its natural attosecond to sub-femtosecond timescales. Ultrafast processes are conventionally studied…
In the recent Baksan Experiment on Sterile Transitions (BEST), a suppressed rate of neutrino absorption on a gallium target was observed, consistent with earlier results from neutrino source calibrations of the SAGE and GALLEX/GNO solar…
The rate at which matter emits or absorbs light can be modified by its environment, as dramatically exemplified by the widely-studied phenomenon of superradiance. The reverse process, superabsorption, is harder to demonstrate due to the…
Two-dimensional (2D) materials have attracted wide-spread interest due to their unique and tunable properties. Their optoelectronic, mechanical, and thermal properties are greatly influenced by crystal defects, which are, in turn, used to…
Ultrafast optical pump-probe spectroscopy is a powerful tool to study dynamics in solid materials on femto- and picosecond timescales. In such experiments, a pump pulse induces dynamics inside a sample by impulsive light-matter interaction,…
Ultrafast time-resolved differential reflectivity of Bi2Se3 crystals is studied using optical pump-probe spectroscopy. Three distinct relaxation processes are found to contribute to the initial transient reflectivity changes. The deduced…
Perfect, narrow-band absorption is achieved in an asymmetric 1D photonic crystal with a monolayer graphene defect. Thanks to the large third order nonlinearity of graphene and field localization in the defect layer we demonstrate the…
Ongoing developments in ultrafast X-ray sources offer powerful new means of probing the com- plex non-adiabatically coupled structural and electronic dynamics of photoexcited molecules. These non-Born-Oppenheimer effects are governed by…
The question of optical bandgap anisotropy in the monoclinic semiconductor $\beta$-Ga2O3 was revisited by combining accurate optical absorption measurements with theoretical analysis, performed using different advanced computation methods.…
Radiation tolerance is determined as the ability of crystalline materials to withstand the accumulation of the radiation induced disorder. Nevertheless, for sufficiently high fluences, in all by far known semiconductors it ends up with…
We studied the influence of defect states on the laser excitation process in silicon using time-dependent density functional theory. We assumed two types of point defects: interstitial oxygen and silicon vacancies. We found that the…
Beta-phase gallium oxide ($\beta$-Ga$_2$O$_3$) research has gained accelerated pace due to its superiorly large bandgap and commercial availability of large-diameter native substrates. However, the high acceptor activation energy obstructs…
A detailed defect energy level map was investigated for heterostructures of 26 unit cells of LaAlO3 on SrTiO3 prepared at a low oxygen partial pressure of 10-6 mbar. The origin is attributed to the presence of dominating oxygen defects in…
The dynamics of excitations with different symmetry is investigated in the superconducting (SC) and normal state of the high-temperature superconductor Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ (Bi2212) using optical pump-probe (Pp)…