Atomic Physics
Using Resonant Pulsed Rydberg Field-ionization (RPRFI) technique, we generate low-energy electron bunches at high repetition rates. By combining continuous-wave laser excitation with a pulsed electric field, this method selectively ionizes…
A huge difference in the harmonic yield from the two topological phases of finite, dimerizing linear chains in laser fields has recently been observed in all-electron time-dependent density functional simulations [D. Bauer, K.K. Hansen,…
We present a method to precisly measure the frequencies of transitions to high-$n$ Rydberg states of the hydrogen atom which are not subject to uncontrolled systematic shifts caused by stray electric fields. The method consists in recording…
The Hamiltonian for the one-dimensional SSH chain is one of the simplest Hamiltonians that supports topological states. This work considers between one and three finite SSH chains with open boundary conditions that either share a lattice…
We report measured and calculated values of radiative decay rates and vibrational branching fractions for the A$^2\Pi$ state of MgF. The decay rate measurements use time-correlated single photon counting with roughly 1% total uncertainty.…
We propose a novel scheme for probing vibronic coherence in charge migration in molecules utilizing strong field sequential double ionization. To demonstrate the feasibility of this approach, we perform full simulations of a pump-probe…
Microwave electric field sensing is of importance for a wide range of applications in areas of remote sensing, radar astronomy and communications. Over the past decade, Rydberg atoms, owing to their exaggerated response to microwave…
We present enhanced sensing of radio frequency (RF) electric fields (E-fields) by the combined polarizability of Rydberg atoms and the optimized local oscillator (LO) fields of supergheterodyne receiving. Our modified theoretical model…
We explore the feasibility of extracting electroweak observables from a measurement of atomic parity violation in hydrogen. Our proposed quantum-control scheme focuses on the $2s-3s$ or $2s-4s$ transitions in hydrogen. This work is…
We demonstrate laser frequency stabilization with at least 6 GHz of offset tunability using an in-phase/quadrature (IQ) modulator to generate electronic sidebands (ESB) on a titanium sapphire laser at 714 nm and we apply this technique to…
We use quantum-logic spectroscopy (QLS) and interrogate rotational transitions of a single CaH+ ion with a highly coherent frequency comb, achieving a fractional statistical uncertainty for a transition line center of 4 x 10^-13. We also…
Two vertical-external-cavity surface-emitting laser (VECSEL) systems producing ultraviolet (UV) radiation at 235 nm and 313 nm are demonstrated. The systems are suitable for quantum information processing applications with trapped beryllium…
We have built and operated a cryogenic Penning trap arrangement that allows for the efficient production, selection, and long-term storage of highly charged atomic ions. In close similarity to an electron-beam ion trap (EBIT) it works by…
The atomic mass of uranium-238 has been determined to be $238.050\,787\,618(15)\,\text{u}$, improving the literature uncertainty by two orders of magnitude. It is obtained from a measurement of the mass ratio of $^{238}$U$^{47+}$ and…
Rotationally-resolved Fourier-transform spectra of laser-induced fluorescence (LIF) $A^1\Sigma^+_u\sim b^3\Pi_u \rightarrow X^1\Sigma^+_g$ of K$_2$ molecules were recorded and analyzed yielding 4053 term values of spin-orbit (SO) coupled $A…
The LiFr diatomic represents a promising candidate for indirect laser cooling that has not yet been investigated not theoretically or experimentally. The potential energy curves of the ground and low_lying excited states of the LiFr…
The essence of atomic structure theory, quantum chemistry, and computational materials science is solving the multi-electron stationary Schr\"odinger equation. The Quantum Monte Carlo-based neural network wave function method has surpassed…
We investigated the absence of certain bright peaks in Autler-Townes laser excitation spectra of alkali metal atoms. Our research revealed that these dips in the spectra are caused by a specific architecture of adiabatic (or…
The so-called proton radius puzzle (the current discrepancy of proton radii determined from spectroscopic measurements in ordinary versus muonic hydrogen) could be addressed via an accurate measurement of the Rydberg constant, because the…
We apply deep learning for retrieval of the time-dependent bond length in the dissociating two-dimensional H$_2^{+}$ molecule using photoelectron momentum distributions. We consider a pump-probe scheme and calculate electron momentum…