2 PhD positions in experimental atomic physics
We are looking for two highly-motivated students with excellent laboratory skills for performing state-of-the-art atomic physics experiments within the Quantum Flagship project iqClock.
The strontium quantum gases group, headed by Prof. Florian Schreck, is part of the Quantum Gases and Quantum Information (QG&QI) cluster at the University of Amsterdam. The main focus of the group is the exploitation of Sr quantum gases for novel precision measurement techniques and the study of many-body physics.
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.
This project has three parts. In one part we will create a superradiant laser on a kHz line transition, collaborating with the group of Jan Thomsen in Copenhagen. In the second part we’ll attempt to build a superradiant clock on the mHz line of Sr together with the group of Michał Zawada in Torun. The PhD student collaborating with the Torun group has the opportunity to work with them in Poland for up to 1.5 years of the PhD. The third part will be the exploration of the foundations of superradiant lasing in Amsterdam. Our ideas for this part range from the study of many-body effects in driven-interacting systems to cavity-cooling of a stream of atoms to quantum degeneracy, forming a continuous atom laser. The work will be executed in a team of another PhD student, two postdocs, Florian Schreck and an extensive network of collaborators.
 Matthew A. Norcia, Matthew N. Winchester, Julia R. K. Cline and James K. Thompson,Superradiance on the millihertz linewidth strontium clock transition, Science Advances 2, e1601231 (2016).
 Shayne Bennetts, Chun-Chia Chen (陳俊嘉), Benjamin Pasquiou, and Florian Schreck, Steady-State Magneto-Optical Trap with 100-Fold Improved Phase-Space Density, Phys. Rev. Lett. 119, 223202 (2017).
You hold a MSc. or equivalent 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 is of advantage;
- 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.
For more information click "LINK TO ORIGINAL" below.
This opportunity has expired. It was originally published here: