Atomic Physics
We report on the realization of a quantum sensor based on trapped atom interferometry in an optical lattice for the measurement of atom-surface interactions, with sub-micrometer-level control of the mean atom-surface separation distance.…
Molecular predissociation is the spontaneous, nonradiative bond breaking process that can occur upon excitation. In the context of laser cooling, predissociation is an unwanted consequence of molecular structure that limits the ability to…
Chemical reactions in the quantum degenerate regime are described by mixing of matterwave fields. Quantum coherence and bosonic enhancement are two unique features of many-body reactions involving bosonic reactants and products. Such…
The effect of optically driven spin precession discovered by Bell and Bloom [W. E. Bell and A. L. Bloom, Phys. Rev. Lett. 6, 280 (1961)] is widely used nowadays as a basis for numerous experiments in fundamental physics and for diverse…
Long-lived ionic quantum states known as metastable electronic states in highly-charged ions (HCIs) are of great interest in fundamental physics. Especially, it generates transitions with very narrow natural linewidth which is a promising…
We identify a route for the production of $^{87}$Rb$^{133}$Cs molecules in the $\textrm{X} \, ^1\Sigma^+$ rovibronic ground state that is compatible with efficient mixing of the atoms in optical lattices. We first construct a model for the…
We demonstrate co-trapping and sideband cooling of a H$_2^+$ - $^9$Be$^+$ ion pair in a cryogenic Paul trap. We study the chemical lifetime of H$_2^+$ and its dependence on the apparatus temperature, achieving lifetimes of up to…
Relying on the redefined vacuum state approach, and based on one-particle three-loop Feynman diagrams, partial third-order interelectronic corrections to the valence electron energy shift are investigated in Li-like ions. The idea is to…
We present results of relativistic calculations of even order harmonic generation from various atomic targets. The even order harmonics appear due to the relativistic non-dipole effects. We take these relativistic effects into account by…
We report calculations of Delbr\"uck scattering that include all-order Coulomb corrections for photon energies above the threshold of electron-positron pair creation. Our approach is based on the application of the Dirac-Coulomb Green…
In this paper, we investigate the coherent control over a complex multi-level atomic system using the stimulated Raman adiabatic passage (STIRAP). Based on the example of rubidium-87 atoms, excited with circularly-polarized light at the D1…
We report on a study of modulation transfer spectroscopy of the $4\textrm{S}_{1/2}\rightarrow 4\textrm{P}_{1/2}$ ($D_{1}$) transition of naturally abundant potassium in a room-temperature vapour cell. This transition is critical for laser…
Deep learning models have provided huge interpretation power for image-like data. Specifically, convolutional neural networks (CNNs) have demonstrated incredible acuity for tasks such as feature extraction or parameter estimation. Here we…
We present the measurements of individual bound electron $g$ factors of $^{20}\text{Ne}^{9+}$ and $^{22}\text{Ne}^{9+}$ on the relative level of $0.1\,\text{parts}$ per billion. The comparison with theory represents the most stringent test…
We study formation and evolution of the electron wave-packets in the process of strong field ionization of various atomic targets. Our study is based on reformulating the problem in terms of conditional amplitudes, i.e., the amplitudes…
We measured transitions between the hyperfine levels of the electronic ground state of potassium-39 atoms (transition frequency: 460 MHz) as the atoms moved through a periodic magneto-static field produced above the magnetic-stripe domains…
The sensitivity of electric field sensors based on two-photon electromagnetically induced transparency (EIT) involving highly excited Rydberg states in thermal atoms is often limited by the residual Doppler effect and optical power…
We demonstrate a new temperature record for image-current mediated sympathetic cooling of a single proton in a cryogenic Penning trap by laser-cooled $^9$Be$^+$. An axial mode temperature of 170 mK is reached, which is a 15-fold improvement…
We propose and demonstrate a general method to calibrate the frequency-dependent response of self-compensating noble-gas-alkali-metal comagnetometers to arbitrary spin perturbations. This includes magnetic and nonmagnetic perturbations like…
We report on laser cooling of a large fraction of positronium (Ps) in free-flight by strongly saturating the $1^3S$-$2^3P$ transition with a broadband, long-pulsed 243 nm alexandrite laser. The ground state Ps cloud is produced in a…