原子物理
Despite being the dominant force of nature on large scales, gravity remains relatively elusive to experimental measurement. Many questions remain, such as its behavior at small scales or its role in phenomena ascribed to dark matter and…
In quantum metrology and quantum simulation, a coherent non-classical state must be manipulated before unwanted interactions with the environment lead to decoherence. In atom interferometry, the non-classical state is a spatial…
Many energy levels of singly ionised iron (Fe II, $Z=26$) remain uncertain or experimentally unknown. Their identification and spectral line data are required in reliable astrophysical spectral analyses. In motivation for improving the…
We present spectroscopic data for four metastable state clear-out transitions between 399 nm and 412 nm for all even long-lived isotopes of Yb$^+$ as well as their hyperfine structure in $^{171}$Yb$^+$. The strong $^2 \rm{D}_{3/2}…
We have experimentally studied dissociative recombination (DR) of electronically and vibrationally relaxed ArH$^+$ in its lowest rotational levels, using an electron--ion merged-beams setup at the Cryogenic Storage Ring. We report…
We propose a laser resonance chromatography (LRC) experiment on $^{229}$Th$^{3+}$, with the goal of detecting the ion's electronic ground $5f$ $^2$F$_{5/2}$ state and metastable $7s$ $^2$S$_{1/2}$ state by means of their ion mobilities. To…
We study and characterize a quasi-continuous dynamical decoupling (QCDD) scheme that effectively suppresses dominant frequency shifts in a multi-ion optical clock. Addressing the challenge of inhomogeneous frequency shifts in such systems,…
The analytical calculation of the complete $\alpha\,(Z\,\alpha)^6$ one-loop radiative correction to energies of two-body systems with the angular momenta $l>0$, consisting of a pointlike particle and an extended-size nucleus with arbitrary…
We report on broad instantaneous bandwidth microwave spectrum analysis with hot $^{87}\mathrm{Rb}$ atoms in a microfabricated vapor cell in a large magnetic field gradient. The sensor is a MEMS atomic vapor cell filled with isotopically…
We show that applying a few-femtosecond mid-infrared laser pulse parallel to the backbone of a halogenated, conjugated organic molecule induces localized ionization followed by long-lasting field-free charge migration (CM). Through…
Radiative corrections to electronic structure are characterized by perturbative expansions in $\alpha$ and $Z\alpha$, where $\alpha$ is the fine-structure constant and $Z$ is the nuclear charge. A formulation of the leading-order…
We outline a general formalism for treating vacuum polarization phenomena within an effective field expansion. The coupling between source charges and virtual fields is examined from the perspectives of electrostatic potentials, induced…
Only bosonic molecular species have been directly laser cooled to date, primarily due to an abundance of bosonic isotopes in nature and to their simpler hyperfine structure. Fermionic molecules provide new opportunities for ultracold…
The accurate determination of atom numbers is an ubiquitous problem in the field of ultracold atoms. For modest atom numbers, absolute calibration techniques are available, however, for large numbers and high densities, the available…
We studied the effect of nuclear-quadrupole interactions on the field-free impulsive alignment of different asymmetric-top molecules. Our analysis is focused on the influence of the hyperfine- and rotational-energy-level structures. These…
We propose and demonstrate a novel method for measuring the polarization direction of a microwave electric field in a single measurement using a Rydberg atom-based mixer with two orthogonally polarized local microwave electric fields.…
Understanding molecular state evolution is central to many disciplines, including molecular dynamics, precision measurement, and molecule-based quantum technology. Details of the evolution are obscured when observing a statistical ensemble…
Modern applications of atomic physics, including the determination of frequency standards, and the analysis of astrophysical spectra, require prediction of atomic properties with exquisite accuracy. For complex atomic systems,…
The helium atom, with one nucleus and two electrons, is a prototypical system to study quantum many-body dynamics. Doubly-excited states, or quantum states in which both electrons are excited by one photon, are showcase scenarios of…
We investigate the photoionization dynamics of atoms subjected to intense, ultrashort laser pulses through the use of quantum trajectories. This method provides a unique and consistent framework for examining electron dynamics within a…