Atomic Physics
We report our method for transporting ultracold atoms over macroscopic distances and trapping them back in a vertical mixed trap, consisting of the superposition of a vertical lattice and a transverse confinement beam. The transport is…
Ultralong-range Rydberg molecules (ULRM) are highly imbalanced bound systems formed via the low-energy scattering of a Rydberg electron with a ground-state atom. We investigate for $^{23}$Na the $d$-state and the energetically close-by…
We develop and demonstrate a spectroscopic method for Rydberg-Rydberg transitions using a phase-controlled and -modulated, standing-wave laser field focused on a cloud of cold $^{85}$Rb Rydberg atoms. The method is based on the…
The process of Compton scattering by a free electron with subsequent reemission of one or two photons is considered in the assumption of finite interaction time. The corresponding cross sections are obtained in the framework of relativistic…
Positronium (Ps) has emerged as a promising test particle within the QUPLAS collaboration for investigating the gravitational effect. In this work, we present a novel approach to generate a monoenergetic and highly coherent Ps beam by…
We employ the two-band density-matrix equations and time-dependent density functional theory to calculate high-order harmonic generation (HOHG) in graphene under a femtosecond laser irradiation. Our investigation uncovers a striking…
We develop a theoretical model for calibrating the absorption imaging of cold atoms under high magnetic fields. Comparing to zero or low magnetic fields, the efficiency of the absorption imaging becomes lower while it requires an additional…
We demonstrate partial-transfer absorption imaging as a technique for repeatedly imaging an ultracold atomic ensemble with minimal perturbation. We prepare an atomic cloud in a state that is dark to the imaging light. We then use a…
We investigate sub-Doppler laser cooling of bosonic potassium isotopes, whose small hyperfine splitting has so far prevented cooling below the Doppler temperature. We find instead that the combination of a dark optical molasses scheme that…
Emission spectra of neodymium (Nd, Z=60) were recorded using Penning and hollow cathode discharge lamps in the region 11500-54000 cm$^{-1}$ (8695-1852 \r{A}) by Fourier transform spectroscopy at resolving powers up to 106. Wavenumber…
We have developed and demonstrated a scheme to achieve rotationally-closed photon cycling in polyatomic molecules with complex hyperfine structure and sensitivity to hadronic symmetry violation, specifically $^{171}$YbOH and $^{173}$YbOH.…
Ion mobilities of Lr^+ (Z = 103) and of its lighter chemical homolog Lu^+ (Z = 71) in helium were calculated for the ground state ^1S_0 and the lowest metastable state ^3D_1. To this end we applied the multi-reference configuration…
A six-dimensional potential energy surface is constructed for the spin-polarized triplet state of CaF-CaF by \textit{ab initio} calculations at the CCSD(T) level of theory, followed by Gaussian process interpolation. The potential is…
We demonstrate Rydberg blockade due to the charge-dipole interaction between a single Rb atom and a single RbCs molecule confined in optical tweezers. The molecule is formed by magnetoassociation of a Rb+Cs atom pair and subsequently…
We present a general mathematical procedure to handle interactions described by a Morse potential in the presence of a strong harmonic excitation. We account for permanent and field-induced terms and their gradients in the dipole moment…
The implementation of attosecond photoelectron-photoion coincidence spectroscopy for the investigation of atomic and molecular dynamics calls for a high-repetition-rate driving source combined with experimental setups characterized by…
The existence of the fundamental CP-violating interactions inside the nucleus leads to the existence of the nuclear Schiff moment. The Schiff moment potential corresponds to the electric field localized inside the nucleus and directed along…
The Gamma Factory initiative proposes to develop novel research tools at CERN by producing, accelerating and storing highly relativistic, partially stripped ion beams in the SPS and LHC storage rings. By exciting the electronic degrees of…
The elastic collision between two H-like atoms utilizing an ab-initio static-exchange model (SEM) in the center of mass (CM) frame considering the system as a four-body Coulomb problem where all the Coulomb interaction terms in the direct…
Precise spectroscopic analysis of polyatomic molecules enables many striking advances in physical chemistry and fundamental physics. We use several new high-resolution spectroscopic devices to improve our understanding of the rotational and…