Related papers: Two-photon transitions in hydrogen and cosmologica…
Radiative transfer in hydrogen lines in supernova remnant (SNR) shock waves is studied taking into account the population of the hydrogen atom 2s-state. Measurements of Balmer line emission, especially of H~$\alpha$, are often relied upon…
In this paper we compute the emission coming from the direct recombination of free electrons to a given shell (n>=2) during the epoch of cosmological hydrogen recombination. This contribution leads to a total of one photon per recombined…
The calculation of a highly accurate cosmological recombination history has been the object of particular attention recently, as it constitutes the major theoretical uncertainty when predicting the angular power spectrum of Cosmic Microwave…
More than half of the atoms in the Universe recombined via forbidden transitions, so that accurate treatment of the forbidden channels is important in order to follow the cosmological recombination process with the level of precision…
Many superconducting qubit systems use the dispersive interaction between the qubit and a coupled harmonic resonator to perform quantum state measurement. Previous works have found that such measurements can induce state transitions in the…
The total two-photon decay rate of hydrogen-like ions is studied using relativistic quantum electrodynamics. In particular, we analyse how finite nuclear size and QED vacuum polarization corrections affect the decay rate. To calculate these…
We make the first calculation in lattice QCD of two-photon decays of mesons. Working in the charmonium sector, using the LSZ reduction to relate a photon to a sum of hadronic vector eigenstates, we compute form-factors in both the…
We show that temporal two-photon interference effects involving the signal and idler photons created by parametric down-conversion can be fully characterized in terms of the variations of two length parameters--called the biphoton…
The forward fitting of solar flare observations with radiation-hydrodynamic simulations is a common technique for learning about energy deposition and atmospheric evolution during these explosive events. A frequent spectral line choice for…
We describe optimized coherent control methods for two-photon transitions in atoms of a ladder-type three-state energy configuration. Our approach is based on the spatial coherent control scheme which utilizes counter-propagating ultrashort…
We investigate the gauge invariance of the leading logarithmic radiative correction to the two-photon decay width in hydrogenlike atoms. It is shown that an effective treatment of the correction using a Lamb-shift "potential" leads to…
The inhibition of the total HI $n\leftrightarrow 1$ transition rate by delayed resonant reabsorption of HI $(n+1)\to 1$ photons by HI $n\to 1$ line which is possible due to cosmological redshift is considered semi-analytically. The method…
We investigate the temperature dependence of photon coherence properties through two photon interference (TPI) measurements from a single QD under resonant excitation. We show that the loss of indistinguishability is only related to the…
We present a study of two-photon electron capture by H-like uranium ions. The energy of the incident electron was chosen to be in the region with the most significant contribution of the dielectric recombination. We studied the photon…
Cosmological constraints from the cosmic microwave background (CMB) anisotropies rely on accurate theoretical calculations of the cosmic recombination history. Recent work has emphasized the importance of radiative transfer calculations due…
Two--photon decays of Higgs bosons are important channels for the search of these particles in the intermediate mass range at the $pp$ colliders LHC and SSC. Dynamical aspects of the Higgs coupling to two photons can also be studied by…
Doppler-free two-photon spectroscopy is a standard technique for precision measurement of transition frequencies of dipole-forbidden transitions. The accuracy of such measurements depends critically on fitting of the spectrum to an…
We investigate the two-photon decay rate of a highly excited atomic state which can decay to bound states of lower energy via cascade processes. We show that a naive treatment of the process, based on the introduction of phenomenological…
Two-photon E1M1 transition rates are evaluated for heliumlike ions with nuclear charges in the range Z = 50-94. The two-photon rates modify previously published lifetimes/transition rates of 2 3P0 states. For isotopes with nuclear spin I…
We discuss two-photon correlations from the side peaks that are formed when a two-level system emitter is driven coherently, with a detuning between the driving source and the emitter (quasi-resonance fluorescence). We do so in the context…