Postdoc in Cavity Quantum Optomechanics

Monday 14 Nov 22

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Are you also intrigued by the possibility of exploring macroscopic quantum phenomena? And do you want to pursue your scientific career in a world-leading research environment? Then please continue reading.

At the Center for Macroscopic Quantum States (bigQ) at DTU Physics, we seek an excellent, ambitious, and proactive experimentalist for a 2-year postdoc position to drive an experimental project in the highly topical field of cavity quantum optomechanics with ultra-coherent mechanical oscillators, and in close collaboration with three PhD students establishing two different state-of-the-art setups.

Our motivation is to investigate the coherent optomechanical coupling of modes of ultra-coherent mechanical oscillators to an optical cavity field, and the first scientific objective is to controllably measure and subsequently steer the mechanical oscillator into a macroscopic quantum state. The visions include both fundamental investigations of macroscopic quantum phenomena as well as quantum information processing applications of the platform.

bigQ is a Danish national Center of Excellence in quantum information science and technology. The purpose of the center is to explore quantum physics in new macroscopic regimes, deepening our understanding of quantum physics, and speeding up the development of emerging quantum technologies. Our main focus is basic research, but we strongly encourage and support innovation and industry partnerships.

The center offers a stimulating and diverse working environment, comprising around 45 people (with 17 nationalities) including Faculty members, PhD students, postdocs, engineers and an administrator.

The project in short
Quantum optomechanics is a fast-developing field which has gained increased attention in recent years due to the direct access to the motional quantum ground state of macroscopic systems and the ability to obtain ultra-long-lived phononic modes with applications in quantum information processing such as enabling quantum storage and quantum transduction between hybrid systems.

Ultra-coherent mechanical oscillator with extreme quality factors (of nearly 10^9) have been developed in our lab (1,2) and we are now currently establishing a setup for quantum coherent interaction between the modes of the oscillator and a cavity light field. The system is still operating the classical regime and the first job of the postdoc in collaboration with the PhD students is to bring the oscillator into a genuine quantum state by cooling it to the ground state and subsequently steering it into a squeezed state. Numerous quantum protocols with this system are envisioned, and we are confident that the system will provide us with the required competitive edge to reach our goals and deliver high-impact scientific results.

(1) Dennis Høj et al, ”Ultra-coherent nanomechanical resonators based on inverse design”, Nature Communications 12,  5766 (2021),  
(2) Dennis Høj et al, Ultra-coherent nanomechanical resonators based on density phononic crystal engineering,

Responsibilities and qualifications
The project will be carried out in the optomechanics team of the bigQ center, including 6 PhD students, a postdoc, a Research Process Scientist, and one senior researcher. The team currently conducts research into optical feedback cooling of micro-mechanical resonators, development of ultra-coherent mechanical devices using topology optimisation, theoretical quantum optomechanic, bulk Brilliouin acoustic-optics and spin-mechanics. We expect you to actively engage in the team and contribute to and make your expertise available to all of the team’s activities.

We are looking for an exceptional physicist with extraordinary talents and outstanding drive. In particular, we are looking for academic excellence and/or demonstrated scientific achievements. We also expect you to have a strong ability to conceive new ideas, construct high-performance experimental setups, take initiative and leadership, and secure progress of the experimental work on a daily basis. Essential is your internal drive to achieve significant and ground-breaking results.

We expect you to

  • be excited about large challenges and enjoy solving them.
  • have an extraordinary drive towards achieving groundbreaking results.
  • enjoy working in a team, be excited about sharing your expertise with other group members and at the same time have an open-minded spirit.
  • love physics discussions and participating in thoughtful conversations.
  • make things work and deliver!

Further qualifications
You should be motivated and dedicated to do research of the highest standards, be able to work closely with other team members, and share our values of scientific curiosity and creativity. We require demonstrated expertise in experimental quantum optics, preferably with proficiency in optomechanics. Expertise in some of the following areas is expected:

  • design and construction of room temperature optical setups,
  • homodyne tomography,
  • fiber optics,
  • cryogenics
  • electronics development,
  • numerical simulations,
  • Python programming.

As a formal qualification, you must hold a PhD degree (or equivalent).

We offer
DTU is a leading technical university globally recognized for the excellence of its research, education, innovation and scientific advice. We offer a rewarding and challenging job in an international environment. We strive for academic excellence in an environment characterized by collegial respect and academic freedom tempered by responsibility.

Salary and terms of employment
The appointment will be based on the collective agreement with the Danish Confederation of Professional Associations. The allowance will be agreed upon with the relevant union.

The period of employment is 2 years.

You can read more about career paths at DTU here.

Further information
The project is funded by the Danish National Research Foundation.

Further information may be obtained from Prof. Ulrik Andersen (Center Leader),

You can read more about us on and

If you are applying from abroad, you may find useful information on working in Denmark and at DTU at DTU – Moving to Denmark.

Application procedure
Your complete online application must be submitted no later than 4 December 2022 (Danish time).

Applications must be submitted as one PDF file containing all materials to be given consideration. To apply, please open the link "Apply online", fill out the online application form, and attach all your materials in English in one PDF file. The file must include:

  • Application (cover letter)
  • CV
  • Academic Diplomas (MSc/PhD)
  • List of publications

All interested candidates irrespective of age, gender, disability, race, religion or ethnic background are encouraged to apply.

DTU Physics is a modern department with an emphasis on strong professionalism. We want to be elitist in physics and we demand a lot of our employees and students. We focus on research, teaching and innovation in areas with fundamental challenges and application potentials. We cover areas such as surface physics, materials science, computer-based material calculations, fluid dynamics, biophysics, plasma physics and quantum physics, and we encourage collaboration between the areas.
Applications range from sustainable energy and the materials of the future to quantum technology.

Technology for people
DTU develops technology for people. With our international elite research and study programmes, we are helping to create a better world and to solve the global challenges formulated in the UN’s 17 Sustainable Development Goals. Hans Christian Ørsted founded DTU in 1829 with a clear vision to develop and create value using science and engineering to benefit society. That vision lives on today. DTU has 13,400 students and 5,800 employees. We work in an international atmosphere and have an inclusive, evolving, and informal working environment. DTU has campuses in all parts of Denmark and in Greenland, and we collaborate with the best universities around the world.