PhD position in Molecular Spectroscopy - Precision measurements of trapped H2+

PhD position in Molecular Spectroscopy - Precision measurements of trapped H2+

Published Deadline Location
16 Feb 30 Apr Amsterdam
This PhD project is about precision measurements of weakly-bound states of H2+ in the THz range to test QED predictions. Molecular ions are selectively prepared using Rydberg states, trapped, and sympathetically cooled using Be+ ions.

Job description

We are looking for a motivated and interested PhD-student, with a degree in physics or physical chemistry and with experience in atomic/molecular/optical physics and/or molecular spectroscopy, who wishes to work with us in the international and stimulating environment of the joint Quantum Metrology group at LaserLaB Amsterdam.

This project aims to measure the level structure of weakly-bound molecular states of H2+ with unprecedented accuracy using novel quantum technologies. These transitions in the microwave and THz range are particularly sensitive to the proton-to-electron mass ratio (mp/me) and exotic spin-dependent interactions. For this, you will be involved in developing a novel ion trap for quantum-logic spectroscopy using H2+ (spectroscopy) and Be+ (logic) ions. You will develop a continuous-wave laser system at 313nm (using fiber lasers, periodically poled crystals, and optical cavities for second-harmonic generation) to laser cool Be+ ions, which are then used for sympathetic cooling of the molecular ions. The molecular ions are selectively prepared by field-ionizing the optically excited molecular Rydberg states of H2 (we use extreme-UV, UV and visible laser light). To guide the experimental developments and understand the measured spectra, you will dive into the details of the molecular Hamiltonian, advanced angular momentum theory, optical Bloch equations, laser cooling simulations, and many other topics.

During the PhD, you will engage with various aspects of molecular spectroscopy and experimental physics, including ultrahigh vacuum, CAD design, optics and lasers, electronics, and scientific programming. There is also the possibility of delving into the theory of molecular Rydberg states, photoionization, and photodissociation using multichannel quantum-defect theory.


Vrije Universiteit Amsterdam (VU)


  • Bachelor/Master in physics or physical chemistry
  • Affinity for spectroscopy and molecular physics.
  • Most important is that you are bright, enthusiastic, work well in a team, are eager to learn, and of course that you are enthusiastic about this intriguing project!

As a university, we strive for equal opportunities for all, recognizing that diversity takes many forms. We believe that diversity in all its complexity is invaluable for the quality of our teaching, research, and service. We are always looking for talent with diverse backgrounds and experiences. This also means that we are committed to creating an inclusive community so that we can use diversity as an asset.

We realize that each individual brings a unique set of skills, expertise, and mindset. Therefore we are happy to invite anyone who recognises themselves in the profile to apply, even if you do not meet all the requirements.

Conditions of employment

Fixed-term contract: 1 year.

A challenging position in a socially engaged organisation. At VU Amsterdam, you contribute to education, research and service for a better world. And that is valuable. So in return for your efforts, we offer you:
  • a salary of minimum € 2.770,00 (PhD) and maximum € 3.539,00 (PhD) gross per month, on a full-time basis. This is based on UFO profile PhD candidate. The exact salary depends on your education and experience.
  • a full-time position (1.0 FTE). Your employment contract will initially last 1 year. If there is sufficient perspective, this will be extended to a total of 4 years.

We also offer you attractive fringe benefits and regulations. Some examples:
  • A full-time 38-hour working week comes with a holiday leave entitlement of 232 hours per year. If you choose to work 40 hours, you have 96 extra holiday leave hours on an annual basis. For part-timers, this is calculated pro rata.
  • 8% holiday allowance and 8.3% end-of-year bonus
  • contribution to commuting expenses
  • optional model for designing a personalized benefits package
  • a wide range of sports facilities which staff may use at a modest charge


Vrije Universiteit Amsterdam

QMLA group in the Department of Physics and Astronomy

The Quantum Metrology and Laser Applications group at LaserLaB, Vrije Universiteit Amsterdam, is a very international group, consisting of some 20 strongly collaborating senior and junior scientists. The group focuses on precision measurements of atomic and molecular systems, using advanced laser techniques as well as techniques to cool the motion of atoms and molecules. For this, they use the joint infrastructure at LaserLaB, with a variety of lasers ranging from ultrastable to ultrafast, connected to atomic clocks and frequency comb lasers. The goals are to test fundamental theories of physics (like Quantum Electrodynamics), to determine fundamental constants (like the proton-electron mass ratio), and to search for physics beyond the Standard Model, such as fifth forces and extra dimensions.

Faculty of Science
Researchers and students at VU Amsterdam’s Faculty of Science tackle fundamental and complex scientific problems to help pave the way for a sustainable and healthy future. From forest fires to big data, from obesity to malnutrition, and from molecules to the moon: we cover the full spectrum of the natural sciences. Our teaching and research have a strong experimentally technical, computational and interdisciplinary nature.

We work on new solutions guided by value-driven, interdisciplinary methodologies. We are committed to research, valorisation and training socially engaged citizens of the world who will make valuable contributions to a sustainable, healthy future.

Are you interested in joining the Faculty of Science? You will join undergraduate students, PhD candidates and researchers at the biggest sciences faculty in the Netherlands. You will combine a professional focus with a broad view of the world. We are proud of our collegial working climate, characterised by committed staff, a pragmatic attitude and engagement in the larger whole. The faculty is home to over 11,000 students enrolled in 40 study programmes. It employs over 1,600 professionals spread across 10 academic departments.

Vrije Universiteit Amsterdam
Vrije Universiteit Amsterdam stands for values-driven education and research. We are open-minded experts with the ability to think freely. - a broader mind. Maintaining an entrepreneurial perspective and concentrating on diversity, significance and humanity, we work on sustainable solutions with social impact. By joining forces, across the boundaries of disciplines, we work towards a better world for people and planet. Together we create a safe and respectful working and study climate, and an inspiring environment for education and research. Learn more about our codes of conduct

We are located on one physical campus, in the heart of Amsterdam's Zuidas business district, with excellent location and accessibility. Over 5,500 staff work at the VU and over 30,000 students attend academic education.

Diversity is the driving force of the VU. The VU wants to be accessible and receptive to diversity in disciplines, cultures, ideas, nationalities, beliefs, preferences and worldviews. We believe that trust, respect, interest and differences lead to new insights and innovation, to sharpness and clarity, to excellence and a broader understanding.

We stand for an inclusive community and believe that diversity and internationalisation contribute to the quality of education, research and our services.

Therefore, we are always searching for people whose backgrounds and experience contribute to the diversity of the VU community.

Additional information

Are you interested in this position and do you believe that your experience will contribute to the further development of the project? In that case, we encourage you to submit your application.

Please provide a detailed CV, your diploma, a cover letter, and the names and contact details of two potential references.

Applications will be considered until the position is filled.


  • PhD
  • Natural sciences
  • €2770—€3539 per month
  • University graduate
  • 3751


Vrije Universiteit Amsterdam (VU)

Learn more about this employer


De Boelelaan 1085, 1081HV, Amsterdam

View on Google Maps

Interesting for you


Apply for this job

Apply for this job

This application process is managed by the employer (Vrije Universiteit Amsterdam (VU)). Please contact the employer for questions regarding your application.

Thank you for applying

Please contact the employer for questions regarding your application.

Tip: save this job as favorite in your AcademicTransfer account. This gives you an immediate overview and makes it easy to find the job later on. No account yet? Create it now and take advantage of other useful functionalities too!

Application procedure

Application procedure

Make sure to apply no later than 30 Apr 2024 23:59 (Europe/Amsterdam).