Related papers: Line Profile Asymmetry in Precision Spectroscopy
We demonstrate a strong influence of the phonon environment on the coherent dynamics of the quantum dot (QD)-cavity system in the quantum strong coupling regime. This regime is implemented in the nonlinear QD-cavity QED and can be reliably…
We evaluate the effect of variations in the electron-impact excitation cross sections on the non-LTE line formation for hydrogen in early-type stars. While the Balmer lines are basically unaffected by the choice of atomic data, the Brackett…
Fundamental principles of quantum field theory such as Lorentz invariance, CPT symmetry and locality may be tested to extremely high precision in atomic and molecular spectroscopy. The narrow natural linewidth of rovibrational states in the…
We present the results of several collisional-radiative models describing optically-thin emissivities of the main lines in neutral helium formed by recombination, for a grid of electron temperatures and densities, typical of H II regions…
Collision broadening by molecular hydrogen of sodium and potassium is one of the major broadening mechanisms in the atmospheres of brown dwarf stars and exoplanets at an effective temperature of about 1000K. The accurate computation of line…
We employ two-dimensional (2D) coherent, nonlinear spectroscopy to investigate couplings within individual InAs quantum dots (QD) and QD molecules. Swapping pulse ordering in a two-beam sequence permits to distinguish between rephasing and…
The spectral line shapes for hydrogen-like heavy ion emitters embedded in strongly correlated two-component electron-ion plasmas are investigated with numerical simulations. For that purpose the microfield fluctuations are calculated by…
In the context of the noncommutative QED we consider few phenomena which reflect the noncommutativity. In all of them the new interactions in the Feynmann diagrams that are responsible for the deviation from the standard QED results. These…
We investigate theoretically the effect of spatial asymmetry on the energy and momentum transfer rates in a double-quantum-well system using balance equation approach. Our study is limited to the linear regime where the applied electric…
Interdependencies between experimental spectra, representing line or plane projections of electronic densities, are derived from their consistency and symmetry conditions. Some additional relations for plane projections are obtained by…
The limits of linear electrodynamics are reviewed, and possible directions of nonlinear extension are explored. The central theme is that the qualitative character of the empirical successes of quantum electrodynamics must be used as a…
We perform non-LTE calculations of lithium in late-type stars for a wide range of stellar parameters, including quantum mechanical cross-sections for collisions with neutral hydrogen and the negative hydrogen ion. Non-LTE abundance…
We investigate nonresonant contributions to resonant Rayleigh scattering cross sections of atoms. The problematic nonresonant contributions set a limit to the accuracy to which atomic spectra determine energy levels. We discuss the…
We formulate a generalization of Higgs effective field theory (HEFT) including arbitrary number of extra neutral and charged Higgs bosons (generalized HEFT, GHEFT) to describe non-minimal electroweak symmetry breaking models. Using the…
Nonlinear effects in emission and absorption spectra of gaseous systems are considered. It is shown that level splitting can be detected spectroscopically even if it is below the Doppler width. Conditions for distinguishing interference…
Spectral lines emitted by plasmas provide information about the thermodynamic conditions, the degree of randomness or the interactions prevailing in the medium. Collisions by plasma electrons penetrating the extent of bound-electron…
We investigate nonlinear one- and two-dimensional photonic crystals by applying a finite element-iterative method.Numerical results show the essential influence of nonlinear elements embedded into a quarter-wave stack and the sharp photonic…
Precision spectroscopy of simple atomic systems has refined our understanding of the fundamental laws of quantum physics. In particular, helium spectroscopy has played a crucial role in describing two-electron interactions, determining the…
Transition frequencies and fine-structure splittings of the $2\,{}^3\!S_1 \rightarrow 2\,{}^3\!P_{\!J}$ transitions in helium-like $^{12}\mathrm{C}^{4+}$ were measured by collinear laser spectroscopy on a 1-ppb level. Accuracy is increased…
A status report is given of some recent theoretical and experimental investigations looking for signals of Lorentz violation in QED. Experiments with light, charged particles, and atoms have exceptional sensitivity to small shifts in energy…