Open positions
For positions at Ferdinand-Braun Institut, please visit: fbh-berlin.de/karriere
We welcome inquiries for Postdocs, Ph.D. students, and visiting scientists joining our team. Various positions may become available at any time. Interested candidates should contact us.
21.02.2023
Bachelor / Master Thesis: Implementation of a laser system for alkali vapor MEMS cell activation
Project description
We are looking for motivated Bachelor or Master Students to work with us on optical frequency references using atomic rubidium. The goal of this thesis is to develop a setup for activating micro-integrated Rb vapor spectroscopy cells, i.e. releasing elementary rubidium from a Rb dispenser pill by a high power laser. These cells shall be used in optical atomic clocks based on two-photon spectroscopy of rubidium for potential applications in space missions.
As a Bachelor or Master student working on this project at the HU, your tasks can include:
- Setup and characterization of two lasers operating at 780 nm and 1064 nm, respectively.
- Building an optical system that uses these lasers and a camera system to perform the MEMS cell activation.
- Realizing computer control of the experimental setup, such as translation stages, image acquisition, and laser control.
- Conducting initial experiments on MEMS cell activation with samples produced at the FBH and developing appropriate protocols for measurement and activation.
- Exploring in-situ absorption spectroscopy techniques during the activation process and performing initial trial runs.
- Evaluating key performance parameters of the setup and the activated MEMS cells.
Within this work you will learn about the design of laser systems, optics and imaging, laser spectroscopy and atomic physics as well as computer control of experimental setups. You will thereby gain hands on experience in experimental optical science with cutting edge technology.
Prerequisites
While a background in Laser Physics, Atomic Physics, Spectroscopy, or Optical Technologies is desirable, it is not mandatory for this work. If you are passionate and eager to learn, we encourage you to apply. If you have any questions or are interested in this opportunity, please don’t hesitate to reach out to us.
Contact
M.Sc. J. Kluge: julienphysik.hu-berlin.de
Dr. K. Döringshoff: kdoeringphysik.hu-berlin.de
Dr. M. Krutzik: markus.krutzikphysik.hu-berlin.de

19.04.2022
Master Thesis (Theory): Uncertainty relations in quantum-optical light-matter interactions
Project description
Modern quantum sensors on the basis of ultra-cold atoms allow for an unprecedented experimental accuracy and have shown to be useful in fundamental science and real-world applications alike. With the pursuit of miniaturization and advancing experimental finesse, testing the boundaries of what theoretical physics can predict has become viable. In this master project, we will ask the question, what are the fundamental uncertainties in using atomic quantum sensors? Clearly, the Heisenberg uncertainty relation is one part of the story. But it leaves the effects of, say, temperature, material-modified vacuum fluctuations and complicated system-bath couplings in nonequilibrium situations simply untouched. Due to the latter, the precision that is actually achieved often exceeds Heisenberg’s relation. We aim to explore that discrepancy.
Working with us, you will learn more about:
• Quantum Vacuum and its macroscopic effects
• Light-matter interaction and nonequilibrium statistical physics
• Solving equations (asymptotically) in order to gain physical intuition
Prerequisites
Openness to work with analytical as well as numerical mathematical tools. Solid background in theoretical physics, in particular quantum mechanics, statistical physics, and electrodynamics, is helpful.
Contact
Dr. Daniel Reiche: reichephysik.hu-berlin.de
Dr. Markus Krutzik: markus.krutzikphysik.hu-berlin.de
People with an international history or diverse background and identity are specifically encouraged to apply.

19.04.2022
Berlin School of Optical Sciences & Quantum Technologies (BOS.QT)
BOS.QT is a joint Graduate School of the Physics Departments of Humboldt-Universität zu Berlin, the Technische Universität Berlin and Freie Universität Berlin in partnership with renowned Berlin research institutes of the Leibniz Association, the German Aerospace Center (DLR), the Max-Born-Institute, the Fraunhofer such as the Max-Planck-Society and offers a wide range of academic training and an excellent research environment for acquiring a doctoral degree in natural sciences (Dr. rer. nat.) at one of the participating universities.
For the summer term 2022 the following positions are open:
- Compact Optical Clocks and Atomic Sensors
Humboldt Universität zu Berlin and Ferdinand-Braun-Institute gGmbH
Contact: Dr. Markus Krutzik (markus.krutzikphysik.hu-berlin.de)
Fur further information on the job description see: https://blogs.tu-berlin.de/ioap_bosqt/jobs
Successful applicants can also apply for a membership to BOS.QT.