On Wednesday 11th of October our weekly AMOPP seminar was given by Dr. Martin Zeppenfeld from the Rempe Group at the Max Planck institute for quantum optics in Garching, Germany. His talk focused on their experiments involving the manipulation of cold polar molecules which Dr. Zeppenfeld leads. You can visit their website to find out more about their research, and the abstract for his talk is given below.

Abstract:

Polar molecules offer fascinating opportunities for quantum experiments at cold and ultracold temperatures. For example, chemistry at low temperatures features new possibilities such as controlling chemical reactions via electric and magnetic fields or observing reactions based on tunneling through a reaction barrier. Precision measurements on molecules provide insight into fundamental physics, allowing investigation of physics beyond the standard model. Attaining sufficient control over molecules provides opportunities for quantum simulations and quantum information processing.

In my talk I will present two aspects of our work on polar molecules. First, I will present our toolbox of techniques to produce molecule ensembles at very low temperatures. This includes centrifuge deceleration of cryogenic-buffer-gas cooled molecular beams as well as optoelectrical Sisyphus cooling of formaldehyde to sub-millikelvin temperatures. Second, I will present our progress towards quantum experiments coupling polar molecules to Rydberg atoms. As a first step, we have investigated electric field controlled collisions between polar molecules.

On Wednesday 4th of October, we had the privilege of having Professor Iain D. Moore from the University of Jyväskylä as an invited speaker for one of our AMOPP seminars. The seminar focused mainly on the work they have been doing at the various accelerator facilities at JYFL and had a good mix of nuclear and atomic physics content.

Professor Iain D. Moore kindly agreed to provide a copy of his presentation slides which you can download here.

Abstract:

Optical spectroscopy for nuclear and atomic science at JYFL, Finland

Iain D. Moore, University of Jyväskylä

 

High-resolution optical measurements of the atomic level structure readily yield fundamental and model-independent data on nuclear ground and isomeric states, namely changes in the size and shape of the nucleus, as well as the nuclear spin and electromagnetic moments [1]. Laser spectroscopy combined with on-line isotope separators and novel ion manipulation techniques provides the only mechanism for such studies in exotic nuclear systems.

Internationally, there are a myriad of tools in use however these are traditionally variants of two main workhorses in the field – collinear laser spectroscopy and resonance ionization spectroscopy. Following a short overview of the Accelerator Laboratory at the University of Jyväskylä, I will briefly present both techniques and their use in accessing the heavy element region of the nuclear landscape which exhibits rather scarce information from optical studies. This reflects a combination of the difficulty in producing such elements (low production cross sections) and a lack of stable isotopes (thus few optical transitions available in literature). Indeed, this past year has seen a number of exciting developments including optical studies of exotic atoms produced at the level of one atom-at-a-time [2], and high-resolution spectroscopy in supersonic gas expansions [3].

Recently, we have initiated a new program on the actinide elements in collaboration with the University of Mainz. I will summarize the current status of the work which includes collinear laser spectroscopy on Pu, the heaviest element attempted with this particular technique [4]. Our focus has recently turned to the study of the lowest-lying isomeric state in the nuclear chart, ²²⁹Th.  Almost 40 years of research has been invested into efforts to observe the isomeric transition which, if found, may be directly accessed by lasers. In 2016, the community was given a tremendous boost with the unambiguous identification of the state by a group in Munich, providing a stepping stone towards a future realization of a “nuclear clock” [5].

[1] P. Campbell, I.D. Moore and M.R. Pearson, Progress in Part. and Nucl. Phys. 86 (2016) 127.

[2] M. Laataioui et al., Nature 538 (2016) 495.

[3] R. Ferrer et al., Nature Communications 8 (2017) 14520.

[4] A. Voss et al., Phys. Rev. A 95 (2017) 032506.

[5] L. von der Wense et al., Nature 533 (2016) 47.