The Jaynes-Cummings model describes the system of a two-level atom which is interacting with a photon field in a quantum-mechanical framework. We present a Rabi-type experiment that tests this model. Our system comprises the nuclear spin of protons in water and an oscillating magnetic field. We measured the spin-state transition with various numbers of electromagnetic-field quanta involved.
At very low energies, a light neutral particle above a horizontal surface can experience quantum reflection. The quantum reflection holds the particle against gravity and leads to gravitational quantum states (GQS). So far, GQS were only observed with neutrons as pioneered by Nesvizhevsky and his collaborators at ILL. However, the existence of GQS is predicted also for atoms.
The...
In the ALPHA Experiment, laser-cooling of beryllium ions has been introduced to sympathetically cool positrons [1], which is anticipated to increase antihydrogen production [2]. Beryllium ions are generated through Pulsed Laser Ablation [3] and are trapped in the same Penning-Malmberg trap utilized for trapping and preparing antiproton and positron plasmas for antihydrogen synthesis. Cold...
Muonium ($M = \mu^+ + e^-$) is a purely leptonic exotic atom which can be used as an unique probe for New Physics through precision spectroscopy measurements or through a gravity measurement testing the weak equivalence principle on elementary antimatter. We are developing a novel M source based on stopping accelerator muons in a layer of superfluid helium at cryogenic temperatures.
In this...
We present a novel technique for in-vacuum cavity-enhanced UV spectroscopy that allows nearly continuous measurements over several days, minimizing mirror degradation caused by high-power UV radiation. Our method relies on pulsing of the cavity's internal power, which increases the UV intensity to maximum only for short periods when the studied atom is within the cavity mode volume while...
I will describe work performed on a Paul trap where we have demonstrated splitting and merging of mixed-species ion chains containing beryllium and calcium ions. These have a large mass ratio of > 4, which presents a number of complications, including decoupling of motional modes and large differences in mode frequencies, which primarily result from the difference in pseudo potential...
Precision measurements of nuclear charge radii provide important inputs for modern nuclear theory, helping to improve our understanding of nuclear forces. The spectroscopy of muonic atoms is known as a highly precise method for such measurements. However, in the case of low- to medium-Z nuclei, the covered energy range has so far been difficult to access using laser spectroscopy or...
uonic helium is a hydrogen-like atom composed of a helium atom with one of its electrons replaced by a negative muon. Its ground-state hyperfine structure (HFS), resulting from the interaction of the remaining electron and the negative muon magnetic moment, is very similar to muonium but inverted. High-precision measurements of the muonium ground-state HFS interval are recognized as the most...
The complexity and variety of molecules offer promising applications in metrology and quantum information that go beyond what is possible with atomic systems. We aim to study light molecular ions that are amongst the most fundamental and simplest molecules. Their internal structure can be calculated, making them prime candidates for the determination of fundamental constants as well as for...
