Vacancies in the research team of Prof. Dr. Wim Ubachs


If you are interested contact me via e-mail: w.m.g.ubachs@vu.nl

1) Within ERC-Advanced grant Program: Physics Beyond the Standard Model from molecules

PhD position: Precision spectroscopy of H2 and T2 for a test of the Standard Model
This project involves working on precision frequency metrology studies on hydrogen molecules using advanced lasers, combined with atomic clock/frequency comb calibrations. Measurements of transition frequencies of these molecules can be compared with advanced QED calculations. These results on H2 and various molecular hydrogen isotopologues (H2, HD, D2) can be interpreted to search for fifth forces, see e.g. the paper:
Bounds on fifth forces from precision measurements on molecules . In addition the results can be interpreted in serach for extra dimensions or putting constraints on their size in compactification:
Constraints on extra dimensions from molecular spectroscopy .
Experimental target of the laser spectroscopy is to improve the value of the dissociation energy of the hydrogen molecules and the fundamental vibrational splitting. For further background on the test of QED in atoms and molecules see QED-tests. See the FLYER for this position.

2) Within the FOM-Program : The mysterious size of the proton

PhD position: Precision spectroscopy of H2
The aim of this FOM/NWO-funded research program is to perform highly advanced precision spectroscopy in small atomic/molecular systems to investigate the Proton Radius Puzzle. This puzzle emerged in 2010 from precision spectroscopy in normal (electronic) hydrogen and muonic hydrogen (where the electron is replaced with a muon). The finite size of the proton causes small energy shifts in the spectrum, so the proton size can be determined by precision spectroscopy. However, the proton size obtained from electronic and muonic hydrogen differ by 4% (> 6 standard deviations) which is still a mystery. We will measure the effect of nuclear size in the hydrogen molecule. This project involves working on precision frequency metrology studies on hydrogen molecules using advanced lasers, combined with atomic clock/frequency comb calibrations.
The research program will be executed in a team with several students and PostDocs. We will extend the studies on hydrogen to tritium isotopes (T2, DT, HT) for which we collaborate with the Karlsruhe Institute of Technology, where part of the measurements will be performed.
See the FLYER for this position.

3) Within the NWO-Program : The Dutch Astrochemistry Network

PhD position: Photoabsorption and dissociation of CH and carbon-based radicals
At LaserLaB VU University Amsterdam we have an opening for a PhD student working on the spectroscopy of carbon-based molecules in connection to the chemistry of the interstellar medium. Several techniques will be employed for the spectroscopy: cavity ring-down laser spectroscopy, laser-induced fluorescence, multi-photon ionization. Carbon-based radicals will be produced in plasma jet expansions. The project is connected to the long-standing problem of the Diffuse Interstellar Bands. Part of the experiments will be performed at the Soleil synchrotron in Paris using the unique Fourier-transform vacuum ultraviolet spectrometer fed with VUV from the synchrotron. The work is part of a larger consortium of the Dutch Astrochemistry Network with several groups (including 12 young scientists) working in collaboration.
See the FLYER for this position.

4) Within the FOM-Program : The electron's dipole moment

PhD position: Building a source of cold and dense BaF molecules to measure the electron dipole moment
Within a recently awarded FOM program, we are starting an exciting new project on a precision measurement of the electric dipole moment (EDM) of the electron. This property, which is predicted by the Standard Model of particle physics to be extremely small, is a powerful probe to explore physics beyond this Standard Model. All extensions to the Standard Model, most prominently supersymmetry, naturally predict an electron EDM that is just below the current experimental limits - and we aim to improve on the best current measurement by at least an order of magnitude. To do so we will perform a precision measurement on a slow beam of laser-cooled BaF molecules. With this experiment we test physics at energies comparable to those of the Large Hadron Collider.
In the Amsterdam laboratory we will develop a source of a dense and cold molecular beam of BaF molecules, which will be implemented in the comprehensive experiment. See the FLYER for this position.
See also the FOM website.


Information for all positions: contact me by e-mail: w.m.g.ubachs@vu.nl
PhD positions are all for 4 years period with full salary, either from FOM or from VU University. Salary, growing from 2,191 Euro gross per month in the 1st year to 2,801 Euro is supplemented with a holiday allowance of 8% and an end-of-year bonus of 8,33%. After a successful project the candidate will receive a PhD degree (Doctor of Science) from Vrije Universiteit Amsterdam.