2 Postdoc positions in experimental atomic physics

Research / Academic


The Institute of Physics is looking for two highly-motivated Postdocs with excellent laboratory skills for performing state-of-the-art atomic physics experiments within the Quantum Flagship project iqClock.

In the project you will develop a new type of optical clock: a continuously operating superradiant clock. Optical clocks exploit mHz linewidth transitions of atoms as frequency references and can achieve an accuracy that corresponds to going one second wrong over the lifetime of the universe (10-18). Conventional clocks operate by stabilizing a laser on the atomic clock transition and reading out the laser by using an optical frequency comb. The interrogated atoms have to be extremely cold in order for the Doppler effect not to distort the measurement. Preparing a sample of atoms at ultracold temperatures takes time. To bridge that time the clock laser is short-term stabilized on a cavity.

Here we want to improve and simplify the clock by creating a laser from direct emission of light on the clock transition. Since the transition is so narrow an atom will spontaneously emit a photon only every minute or so, which doesn’t give us enough photons to do anything with. To enhance emission we use superradiance. By making it impossible to know which atom in an ensemble emitted a photon, the ensemble will enter a superposition state that is more likely to emit another photon, creating an avalanche effect and usually resulting in a ' superradiant'  flash of light. The main challenge of this project is to prolong this flash to eternity by feeding new atoms into the superradiantly lasing ensemble. This is challenging since the light used to laser cool the atoms from room temperature to the microKelvin regime decoherers the superradiantly lasing ensemble. This challenge can be solved using a new technique that we have developed over the last years in another project that has the goal to build a continuous atom laser. We are able to create the Sr atomic beams with unprecedented brilliance and steady-state Sr samples close to quantum degeneracy. Crucially, this beam of ultracold Sr atoms is available in a region with very little laser cooling straylight, an important ingredient in feeding a superradiantly lasing ensemble forever.

We expect you to assist in guiding PhD students and master students.


You hold a PhD in physics or a related field and are requested to motivate why you apply for the position and to supply a CV.

Other skills/experiences/documents that would benefit your application are:

  • previous laboratory experience in an atomic physics lab;
  • working knowledge of a programming language (matlab, C++ or equivalent);
  • excellent English oral and written communication skills;
  • scientific publications.

To foster diversity in our research group, we will especially appreciate applications from excellent female candidates.

Salary Benefits:

The appointment will be on a temporary basis for the period of two to maximum three years (initial appointment will be for a period of 12 months and after satisfactory evaluation it can be extended).

The monthly gross salary will range between €2,640 and €4,166 (scale 10), based on a full-time appointment. We offer a pension scheme, a holiday allowance of 8% per year, an end-of-year bonus of 8,3% and flexible employment conditions. Conditions are based on the Collective Labour Agreement for Dutch Universities. Favourable tax agreements may apply to non-Dutch applicants.

Work Hours:

38 hours per week


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