328 citations · 1.7k across the 53 of their papers we have counts for
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Vacuum polarization correction to atomic energy levels in the path integral formalism
Sreya Banerjee, Zoltán Harman
Vacuum polarization corrections to the energy levels of bound electrons are calculated using a perturbative path integral formalism. We apply quantum electrodynamics in a framework…
Stringent test of QED with hydrogenlike tin
J. Morgner, B. Tu, C. M. König +11
Inner-shell electrons naturally sense the electric field close to the nucleus, which can reach extreme values beyond for the innermost electrons. Espe…
Ultrastable optical, XUV and soft-x-ray clock transitions in open-shell highly charged ions
Chunhai Lyu, Christoph H. Keitel, Zoltán Harman
Highly charged ions (HCIs) are insensitive to external perturbations and are attractive for the development of ultrastable clocks. However, only a few HCI candidates are known to p…
Tests of physics beyond the Standard Model with single-electron ions
Vincent Debierre, Christoph H. Keitel, Zoltan Harman
A highly effective approach to the search for hypothetical new interactions through isotope shift spectroscopy of hydrogen-like ions is presented. A weighted difference of the g fa…
New Measurement Resolves Key Astrophysical Fe XVII Oscillator Strength Problem
Steffen Kühn, Charles Cheung, Natalia S. Oreshkina +19
One of the most enduring and intensively studied problems of X-ray astronomy is the disagreement of state-of-the art theory and observations for the intensity ratio of two Fe XVII…
Two-photon exchange corrections to the factor of Li-like ions
V. A. Yerokhin, C. H. Keitel, Z. Harman
We report calculations of QED corrections to the factor of Li-like ions induced by the exchange of two virtual photons between the electrons. The calculations are performed wit…
Two-loop virtual light-by-light scattering corrections to the bound-electron factor
V. Debierre, B. Sikora, H. Cakir +4
A critical set of two-loop QED corrections to the factor of hydrogenlike ions is calculated without expansion in the nuclear binding field. These corrections are due to the pol…
electronic factors of the and hyperfine structure constants for the states in Sn I
Asimina Papoulia, Sacha Schiffmann, Jacek Bieroń +7
Large-scale calculations of the electric field gradient, which constitutes the electronic contribution to the electric quadrupole hyperfine constant , were…
Interrogating the temporal coherence of EUV frequency combs with highly charged ions
Chunhai Lyu, Stefano M. Cavaletto, Christoph H. Keitel +1
A scheme to infer the temporal coherence of EUV frequency combs generated from intra-cavity high-order harmonic generation is put forward. The excitation dynamics of highly charged…
Improved access to the fine-structure constant with the simplest atomic systems
H. Cakir, N. S. Oreshkina, I. A. Valuev +4
A means to extract the fine-structure constant from precision spectroscopic data on one-electron ions is presented. We show that in an appropriately weighted difference of the…
Detection of metastable electronic states by Penning trap mass spectrometry
Rima Xenia Schüssler, Hendrik Bekker, Martin Braß +19
State-of-the-art optical clocks achieve fractional precisions of and below using ensembles of atoms in optical lattices or individual ions in radio-frequency traps. Prom…
QED corrections to the factor of Li- and B-like ions
H. Cakir, V. A. Yerokhin, N. S. Oreshkina +4
QED corrections to the factor of Li-like and B-like ions in a wide range of nuclear charges are presented. Many-electron contributions as well as radiative effects on the one-l…
Skyrme-type nuclear interaction as a tool for calculating the finite nuclear size correction to atomic energy levels and the bound-electron factor
Igor A. Valuev, Zoltán Harman, Christoph H. Keitel +1
A state-of-the-art approach for calculating the finite nuclear size correction to atomic energy levels and the bound-electron factor is introduced and demonstrated for a series…
High Resolution Photoexcitation Measurements Exacerbate the Long-Standing Fe XVII Oscillator Strength Problem
Steffen Kühn, Chintan Shah, José R. Crespo López-Urrutia +29
For more than 40 years, most astrophysical observations and laboratory studies of two key soft x-ray diagnostic transitions, and , in Fe XVII ions found oscillator…
Detection of the orbital crossing and its optical clock transition in Pr
H. Bekker, A. Borschevsky, Z. Harman +5
Recent theoretical works have proposed atomic clocks based on narrow optical transitions in highly charged ions. The most interesting candidates for searches of new physics are tho…
-factor of Boronlike Argon
I. Arapoglou, A. Egl, M. Höcker +15
We have measured the ground-state -factor of boronlike argon with a fractional uncertainty of \SI{1.4e-9}{} with a single ion in the newly developed ALP…
The factor of bound electrons as a test for physics beyond the Standard Model
V. Debierre, C. H. Keitel, Z. Harman
The use of high-precision measurements of the factor of few-electron ions and its isotope shifts is put forward as a probe for physics beyond the Standard Model. The contributi…
Resonance strengths for KLL dielectronic recombination of highly charged mercury ions and improved empirical -scaling law
Zoltán Harman, Chintan Shah, Antonio J. González-Martínez +5
Theoretical and experimental resonance strengths for KLL dielectronic recombination (DR) into He-, Li-, Be-, and B-like mercury ions are presented, based on state-resolved DR x-ray…
Theory of the two-loop self-energy correction to the factor in non-perturbative Coulomb fields
B. Sikora, V. A. Yerokhin, N. S. Oreshkina +3
Two-loop self-energy corrections to the bound-electron factor are investigated theoretically to all orders in the nuclear binding strength parameter . The separation of div…
Narrow-band hard-x-ray lasing
Chunhai Lyu, Stefano M. Cavaletto, Christoph H. Keitel +1
Since the advent of x-ray free-electron lasers (XFELs), considerable efforts have been devoted to achieve x-ray pulses with better temporal coherence. Here, we put forward a scheme…
Hyperfine splitting in simple ions for the search of the variation of fundamental constants
Natalia S. Oreshkina, Stefano M. Cavaletto, Niklas Michel +2
Numerous few-electron atomic systems are considered which can be used effectively for observing a potential variation of the fine-structure constant and the electron-proton mas…
Deterministic strong-field quantum control
Stefano M. Cavaletto, Zoltán Harman, Thomas Pfeifer +1
Strong-field quantum-state control is investigated, taking advantage of the full---amplitude and phase---characterization of the interaction between matter and intense ultrashort p…
X-ray fluorescence spectrum of highly charged Fe ions driven by strong free-electron-laser fields
Natalia S. Oreshkina, Stefano M. Cavaletto, Christoph H. Keitel +1
The influence of nonlinear dynamical effects is analyzed on the observed spectra of controversial 3C and 3D astrophysically relevant x-ray lines in neonlike Fe and the A,…
Phase reconstruction of strong-field excited systems by transient-absorption spectroscopy
Z. Liu, S. M. Cavaletto, C. Ott +5
We study the evolution of a V-type three-level system, whose two resonances are coherently excited and coupled by two ultrashort laser pump and probe pulses, separated by a varying…