原子物理
Systematic QED calculations of ionization energies of the $2s$, $2p_{1/2}$, and $2p_{3/2}$ states, as well as the $2p_{1/2}$--$2s$ and $2p_{3/2}$--$2p_{1/2}$ transition energies are performed for Li-like ions with the nuclear charge numbers…
We demonstrate the effect of inter-atomic interaction in highly excited Rydberg atoms via Autler- Townes splitting in cold atoms. We measure the Autler-Townes (AT) splitting of the 5S1/2, F=2 to 5P3/2, F'=3 transition of 87Rb atoms arising…
Time crystals, as temporal analogs of space crystals, manifest as stable and periodic behavior that breaks time translation symmetry. In an open quantum system, many-body interaction subjected to dissipation allows one to develop the time…
We present a comprehensive study of the electronic transitions in neutral cadmium (Cd I) with a focus on forbidden transitions, motivated by recent advances in laser technology and the growing relevance of cadmium in quantum gas research,…
We report the observation and characterization of a high-contrast dual-frequency Doppler-free ground-state crossover resonance in the D1 line of 87Rb.The crossover appears at a two-photon detuning exceeding the natural linewidth of the…
Ionization is one of the basic physical processes, occurring when charged particles penetrate atomic matter. When atoms are bombarded by very dense and compact beams of extreme relativistic electrons, two qualitatively new -- and very…
Quantum-logic spectroscopy has become an increasingly important tool for the state detection and readout of trapped atomic and molecular ions which do not possess easily accessible closed-cycling optical transitions. In this approach, the…
Optical lattice clocks (OLCs) are at the forefront of precision metrology, operating near a standard quantum limit (SQL) set by quantum noise. Harnessing quantum entanglement offers a promising route to surpass this limit, yet there remain…
The vibrational branching ratios from the lowest excited electronic state for $\textrm{SrOCH}_3$, $\textrm{SrNH}_2$, and $\textrm{SrSH}$ are measured at the $< 0.1\%$ level. Spectra are obtained by driving the $\tilde{X} - \tilde{A}$…
Simulations of optical quantum systems are essential for the development of quantum technologies. However, these simulations are often computationally intensive, especially when repeated evaluations are required for data fitting, parameter…
We report on a $^{88}$Sr$^{+}$ single-ion optical clock with an estimated fractional systematic uncertainty of $7.9\times 10^{-19}$. The low uncertainty is enabled by small rf losses, a thorough evaluation of the blackbody-radiation…
We develop machine learning techniques for estimating physical properties of laser-cooled potassium-39 atoms in a magneto-optical trap using only the scattered light -- i.e., fluorescence -- that is intrinsic to the cooling process. In-situ…
Cold atomic clouds are promising platforms for generating correlated photons, but multiple scattering and associated Doppler broadening limit their temporal coherence. Here we demonstrate that cloud geometry provides a powerful means to…
We present ab initio calculations of one-electron quantum electrodynamical corrections to the second-order Zeeman splitting for the $1s_{1/2}$, $2s_{1/2}$, and $2p_{1/2}$ states in highly charged hydrogen-like ions. The self-energy…
We report the enhanced optical transmission in the coherent, off-resonant excitation of Rydberg atom gases at room temperature via a two-photon process. Here thermal resonance-enhanced transparency (TRET) is induced when the detuning of the…
We report on our progress on multi-ion spectroscopy with Yb+ ions. We first characterized the spatial homogeneity of the magnetic- and the rf-field. Subsequently, to equalize the immense AC Stark shifts of the individual ions in a Coulomb…
This study investigates the ionization and excitation processes induced by electron impact between two configurations or superconfigurations. Rate coefficients are calculated for transition arrays or super-transition arrays rather than…
We present the first fully ab initio calculations of collision-induced broadening and shift of spectral lines in antiprotonic helium ($\bar{p}$He$^{+}$) perturbed by atomic helium. To overcome critical limitations of previous studies, we…
Within the framework of the second order of the non-relativistic quantum perturbation theory, the analytical structure and absolute values of the generalized cross-sections of the two-photon resonant single ionization of the K-shell of…
We show experimentally and theoretically that vortex-shaped structures in the photoelectron momentum distribution can be observed for atoms interacting with a single intense elliptically polarized laser pulse. Our analysis reveals that…