Atomic Physics
Precision spectroscopy of atomic hydrogen is an important way to test bound-state quantum electrodynamics (QED), one of the building blocks of the Standard Model. In its simplest form, such a test consists of the comparison of a measured…
Time-resolved measurement of Auger-Meitner (AM) decay [Nature 419, 803 (2002)] marked a milestone in the development of attosecond science. To date, the time constants for the AM decay processes obtained from the time-domain experiments…
The universality of free fall, a cornerstone of Einstein's theory of gravity, has so far only been tested with neutral composite states of first-generation Standard Model (SM) particles, such as atoms or neutrons, and, most recently,…
We investigate a ionising electronic transition under resonant pumping. We demonstrate that, above a critical value of the pump intensity, a novel metastable electronic bound state is created, which can decay into the free electron…
We present two methods to achieve real-time inertial phase compensation in atom interferometers. Both methods, based on jumps of the position of the retroreflection mirror or frequencies of Raman lasers, demonstrate similar state-of-the-art…
We report on the realization of a platform for trapping and manipulating individual $^{88}$Sr atoms in optical tweezers. A first cooling stage based on a blue shielded magneto-optical trap (MOT) operating on the $^1S_0$ -> $^1P_1$…
We describe the design, construction, and characterization of a permanent magnet based, transverse-field Zeeman slower for lithium atoms. We use off-the-shelf compact permanent bar magnets in the Halbach configuration to create a uniform…
The apparent invariance of the strong nuclear force under combined charge conjugation and parity (CP) remains an open question in modern physics. Precision experiments with heavy atoms and molecules can provide stringent constraints on CP…
Radiation during strong-field tunneling ionization is investigated. The spontaneous as well as the coherent components of the radiation are calculated describing the ionization dynamics via the strong field approximation and the role of the…
Rydberg atom radio frequency sensors are unique in a number of ways, including possessing extraordinary carrier bandwidth, self-calibration and accuracy. In this paper, we examine the impact of thermal radiation on Rydberg atom sensors.…
The use of high-precision measurements of the $g$ factor of single-electron ions is considered as a detailed probe for physics beyond the Standard Model. The contribution of the exchange of a hypothetical force-carrying scalar boson to the…
We present a non-invasive spectroscopic technique to measure electric fields in plasma, leveraging large polarizabilities and Stark shifts of Rydberg atoms. Rydberg Stark shifts are measured with high precision using narrow-linewidth lasers…
Spectroscopy of muonic atoms is, to date, the most accurate technique to extract parameters of the nuclear charge density. The same reasons for their heightened sensitivity to nuclear parameters, a large overlap of the muonic wavefunction…
We report a 4.9\,ppb measurement of the positronium $\text{1}^\text{3}\text{S}_\text{1} \to \text{2}^\text{3}\text{S}_\text{1}$ interval using continuous-wave two-photon laser spectroscopy. The transition is detected via photoionization by…
Asymmetric Fano line profiles are frequently encountered, e.g., in the photoionization spectra of atoms and ions. For the fitting of spectral line profiles to experimental spectra the line profiles have to be convolved with the experimental…
We extend a recently developed three-dimensional semiclassical model to study double and triple ionization of Ne driven by infrared laser pulses at various intensities. This model fully accounts for the Coulomb singularity of each electron…
Arrays of optical tweezers form the backbone of neutral atoms analog and digital quantum processors. However, the inter-trap distance remains generally much larger than the size of the tweezers to avoid interference-induced trap…
We report on the existence of exceptional points (EPs) in single-resonance autoionization and provide analytical expressions for their positions in parameter space, in terms of the Fano asymmetry parameter. We additionally propose a…
We present a general method for engineering qudits through individually addressable transitions between Zeeman sublevels, achieved by combining a large linear Zeeman shift with a state-dependent light shift. This approach lifts the…
We report a single-ion optical clock based on the 4S_1/2-3D_5/2 transition of the 40Ca+ ion, operated in a liquid nitrogen cryogenic environment,achieving a total systematic uncertainty of 4.4E-19. We employ a refined temperature evaluation…