Atomic Physics
Using a single calcium ion confined in a surface-electrode trap, we study the interaction of electric quadrupole transitions with a passively phase-stable optical standing wave field sourced by photonics integrated within the trap. We…
When a photon is sent onto an atomic ensemble, it interacts collectively with the $N$ atoms of the sample and not simply with one of them. This results in measurable modifications in the scattering rate, the emission diagram or the temporal…
Accurate spectroscopic measurements of calculable systems provide a powerful method for testing the Standard Model and extracting fundamental constants. Recently, spectroscopic measurements of finite nuclear size effects in normal and…
Molecular laser cooling and trapping requires addressing all spontaneous decays to excited vibrational states that occur at the $\gtrsim 10^{-4} - 10^{-5}$ level, which is accomplished by driving repumping transitions out of these states.…
Carbon $1s$ core-hole excitation of the molecular anion C$_2^-$ has been experimentally studied at high resolution by employing the photon-ion merged-beams technique at a synchrotron light source. The experimental cross section for…
Using the Dirac equation, we study corrections to electron binding energies and hyperfine splittings of atomic hydrogen and hydrogen-like ions due to finite nuclear size (FNS) effects, relativistic QED radiative corrections and nuclear…
Recollision physics and attosecond pulse generation meld the precision of optics with collision physics. As a follow-up to our previous work, we reveal a new direction for the study of electronic structure and multielectron dynamics by…
We analyze the spatial dynamics of polarized atom vapor and present a mathematical method to eliminate the diffusion effect partially. It is found that the diffusion effect of polarized atoms can be regarded as a low pass filter in spatial…
We consider the magnetically tunable Feshbach resonances that may exist in ultracold mixtures of molecules in $^2\Sigma$ states and alkali-metal atoms. We focus on Rb+CaF as a prototype system. There are likely to be Feshbach resonances…
A formula for supershell partition functions, which play a major role in the Super Transition Array approach to radiative-opacity calculations, is derived as a functional of the distribution of energies within the supershell. It consists in…
The uncertainty of the ac Stark shift due to thermal radiation represents a major contribution to the systematic uncertainty budget of state-of-the-art optical atomic clocks. In the case of optical clocks based on trapped ions, the thermal…
We present a novel optimised design for a source of cold atomic cadmium, compatible with continuous operation and potentially quantum degenerate gas production. The design is based on spatially segmenting the first and second-stages of…
Optical Feshbach resonances (OFRs) allow one to control cold atomic scattering, produce ultracold molecules and study atomic interactions via photoassociation spectroscopy. In the limit of ultracold s-wave collisions the strength of an…
This paper outlines the centralised design and production of the Ultra-High-Vacuum sidearm and Laser-Stabilisation systems for the AION Ultra-Cold Strontium Laboratories. Commissioning data on the residual gas and steady-state pressures in…
Motivated by recent measurements for several alkali-metal atoms and alkali-metal-like ions, we perform a detailed study of electric dipole (E1) transition amplitudes in K, Ca+, Rb, Sr+, Cs, Ba+, Fr, and Ra+, which are of interest for…
Precise control of hyperfine matterwaves via Raman excitations is instrumental to a class of atom-based quantum technology. We investigate the Raman spinor control technique for alkaline atoms in an intermediate regime of single-photon…
Production of electron-positron pairs in two oscillating strong electric field pulses with largely different frequencies and durations is considered. In a first scenario, the influence of a low-frequency background field on pair production…
We constructed a transportable 40Ca+ optical clock (with an estimated minimum systematic shift uncertainty of 1.3*10^(-17) and a stability of 5*10^(-15)/sqrt{tau} ) that can operate outside the laboratory. We transported it from the…
Neutral atoms and molecules trapped in optical tweezers have become a prevalent resource for quantum simulation, computation, and metrology. However, the maximum achievable system sizes of such arrays are often limited by the stochastic…
In this work, we have studied the permanent electric dipole moments of singly charged aluminium monohalides in their electronic ground state, X$^2\Sigma$, using Kramers-restricted relativistic configuration interaction method. We report our…