The art of measurement — made in Germany. Striving to perfect it is the mission of the 2,100 employees of PTB, the Physikalisch-Technische Bundesanstalt. As Germany’s national metrology institute and a leading center of research, we operate in an international environment to develop world-class measurement standards. We at PTB work to ensure that people and organizations can trust the measurements they use.

At our Braunschweig site, we are looking to fill the following position in Department 4.4 (Time and Frequency):

Doctoral candidate in physics

Remuneration Group 13 TVöD Bund • Three-year fixed term • Part-time (33.15 hours/week)

Your tasks:
Working Group 4.43 (Optical Clocks with Trapped Ions) has the task to further develop the 173Yb+ isotope for use in an optical clock. These investigations are building on the many years of successful work with the 171Yb+ isotope. Due to the structure of the atomic nucleus of 173Yb+, stronger coupling is expected for the block transition, which would have advantages for the optical clock. However, the larger nuclear spin also entails additional requirements for efficient cooling and state preparation. You will support us by performing the following activities:

• Automating clock operation for the two clock transitions of 173Yb+
• Investigating stability improvement by simultaneously interrogating multiple ions by various means, including entanglement
• Developing protocols for investigating and using the hyperfine transitions of 173Yb+ ions
• Determining systematic frequency shifts for the two clock transitions and drawing up an uncertainty budget
• Expanding the existing Python-based experimental control system with ARTIQ
• Enhancing existing laser setups
• Performing, evaluating, and analyzing comparison measurements with other optical clocks to verify the systematic uncertainties and to identify violations of the equivalence principle and other effects beyond the standard model
• Presenting the research results at international conferences and in scientific journals

Your profile:

• You have completed your university studies (master’s degree or German Diplom) in physics with an overall grade of "very good” or the equivalent for non-German degrees.
• You ideally possess knowledge and experience in the following fields: atomic physics, atom-light interaction, laser cooling of atoms, laser spectroscopy, experimental optics, automated data acquisition, electronics and programming.
• You are highly interested in experimental work and have strong experimental skills.
• You are highly committed and capable of working independently
• You are a strong team player with excellent communication skills.
• You have achieved C1 level in English. German language skills would be an advantage.
• You are willing to travel for work both in Germany and abroad.

We offer:

• Support for your doctoral work: You will carry out research as part of an internationally renowned team and will benefit from PTB’s excellent infrastructure. At PTB, you will be able to concentrate on your doctoral work without having to give lectures. Our support program for doctoral candidates additionally gives you the opportunity to network with your peers at the national and international levels, for example, at scientific conferences.
• Work-life integration: We offer flexible working arrangements and conditions (part time, flextime, work from home, telework, compensation days) to help you manage your family, care and career responsibilities in all of life’s phases.
• Transparent terms: Remuneration in accordance with Germany’s collective agreement for federal-level public service employees (TVöD Bund), 30 days of paid vacation and an employment-based pension plan for employees covered by the collective agreement are just some of the benefits of working at PTB.
• Location benefits: Our attractive campus offers an easy commute for drivers and cyclists as well as very good direct bus services. Plenty of free parking is available.
• Jobticket: We take environmental and climate protection seriously. To encourage commuting by public transportation, we offer a subsidy towards the cost of the Deutschlandticket Job.
• Family friendly: From daycare and dedicated parent-child offices to school holiday childcare, we offer a variety of ways to help you master the family-work balancing act.
• Inclusion: For people with disabilities, we offer an inclusive corporate culture and a range of integrative programs.
• Learning opportunities: We want to help you get ahead by offering a wide range of training and development programs to expand and enhance your skills.
• Health options: Your health is important to us, which is why we offer health promotion and maintenance programs, including workplace sports, a mobile massage service and back care classes.
• Canteen: Situated on our park-like campus grounds, our canteen offers a wide variety of culinary choices every day, including vegetarian/vegan options.

This is important to us: PTB promotes gender equality and strongly encourages applications from female candidates. At the same time, we strive to reflect the diversity of our society. We therefore welcome every application submitted, regardless of the candidate’s gender, cultural or social background, religion, ideology or sexual identity. If equally suited to the position, disabled persons or persons having equivalent status under German law will be given preference.

Your application:

For subject-related questions concerning this position, please contact Department 4.4
Dr. Nils Huntemann, phone: +49 531 592-4430, email: nils.huntemann@ptb.de .

We look forward to receiving your online application by 18 September 2025 under Ref. No. 25-173-4B. Please click on the following button: online application. This will directly lead you to our application portal where you can upload your documents (CV, certificates, letter of motivation). Unfortunately, we cannot accept applications sent via email.

Postal Address: Physikalisch-Technische Bundesanstalt (PTB) | Referat Personal | Bundesallee 100 | 38116 Braunschweig