原子物理
We report a microwave spectroscopy measurement of the muonium $2S_{1/2}-2P_{3/2}$ fine structure transition, yielding a transition frequency of $9871.0 \pm 7.0~\mathrm{MHz}$, in agreement with state-of-the-art QED predictions within one…
Motivated by recent experimental advances, including the ongoing development of an optical atomic clock in singly ionised radium, we perform a detailed theoretical characterisation of Ra+ and its lighter analogue, Ba+. Both ions are of…
We present ab-initio calculations of the electronic differential energy transfer (DET) cross-sections for antiprotons with energies between $3$keV and $1$MeV interacting with helium. By comparison with simulations employing the mean-field…
Single ion optical clocks have shown systematic frequency uncertainties below $10^{-18}$, but typically require more than one week of averaging to achieve a corresponding statistical uncertainty. This time can be reduced with longer probe…
Microfabricated alkali vapor cells enable the miniaturization of atomic sensors, but require collective wafer-level integration of complex features. In many applications, including magnetometers, gyroscopes, magneto-optical traps, and…
We present a scheme to phase-lock a 240 mW, 852 nm distributed Bragg reflector (DBR) laser to a fixed-frequency narrow-linewidth laser with a rapidly tunable frequency offset near 9 GHz. The phase-lock is accomplished by electronic feedback…
We report a 100 kHz linewidth for the 1S0 to 3P1 intercombination line of 88Sr atoms at 689nm in a microfabricated 9x14 x4.4 mm3 vapor cell. This puts an upper bound on the residual gas pressure in the vapor cell of 10 mTorr. The…
We investigated resonant multiphoton excitation of high-angular-momentum planetary states of the strontium atom, a quasi-three-body Coulomb system, both experimentally and theoretically. A series of highly doubly excited electronic states…
We report lifetime measurements of the metastable $6\mathrm{d}\, ^{2}\mathrm{D}_{5/2}$ and $6\mathrm{d}\, ^{2}\mathrm{D}_{3/2}$ states of Ra$^+$. The measured lifetimes, $\tau_{5} = $ 303.8(1.5) ms and $\tau_{3} = $ 642(9) ms, are important…
A comprehensive reevaluation of the root-mean-square nuclear charge radius is presented for the doubly magic $^{208}$Pb extracted from muonic spectroscopy measurements. By integrating rigorous theoretical quantum electrodynamics…
We describe a novel type of interaction between open-shell polar molecules at sub-millikelvin temperatures. This hyperfine van der Waals interaction occurs between two molecules in two rotational states that differ by one quantum. Normally,…
Optically trapped Rydberg atoms are a suitable platform to explore quantum many-body physics mediated by long-range atom--atom interactions that can be engineered through externally applied light fields. However, this approach is limited to…
Atomic data determined by analysis of observed atomic spectra are essential for plasma diagnostics. For each low-ionisation open d- and f-subshell atomic species, around $10^3$ fine structure level energies can be determined through years…
This work presents the rovibrational spectra of the two strongest first overtone bands of the asymmetric stretching mode $\nu_3$ ($2\nu_3^{2+}$ and $2\nu_3^{2-}$) of the hydronium ion, H$_3$O$^+$. The measurements were performed in a…
We investigate a technique for detecting radio-frequency (RF) electric fields in a Cesium (Cs) vapor cell at room temperature by collecting charge from ionized Rydberg atoms and compare its performance with the established method of…
The $5S_{1/2}\rightarrow 5D_{5/2}$ two-photon transition in Rb is of interest for the development of a compact optical atomic clock. Here we present a rigorous calculation of the 778.1~nm ac-Stark shift ($2.30(4)…
Extra-laboratory atomic clocks are necessary for a wide array of applications (e.g. satellite-based navigation and communication). Building upon existing vapor cell and laser technologies, we describe an optical atomic clock, designed…
Optical atomic clocks play a crucial role in fundamental physics, relativistic geodesy, and the future redefinition of the SI second. Standard operation relies on cyclic interrogation sequences, which alternate between atomic interrogation…
Theory can provide important support at all the stages of spectroscopic experiments, from planning the measurements to the interpretation of the results. Such support is particularly valuable for the challenging experiments on heavy,…
Achieving a high population of antihydrogen/hydrogen atoms in the 2S level is essential for spectroscopy measurements testing similarities between matter and antimatter. We propose and examine the efficiency of applying the STIRAP…