J.A. Klärs (Jan)

I am an Associate Professor at the Adaptive Quantum Optics Chair. My research group investigates physical phenomena at the interface between thermodynamics and quantum mechanics in optical and optomechanical systems.

Short biography

In 2006, I completed my master’s degree in physics at RWTH Aachen. In my master's thesis, I theoretically investigated statistical properties of magnets and crystal surfaces. For my PhD, I switched to experimental quantum optics working on the Bose-Einstein condensation of photons at the University of Bonn. After finishing my PhD in 2011, I continued to work at the University of Bonn as project leader for the photon Bose-Einstein condensation experiment. In 2015, I moved to ETH Zürich to work on semiconductor optomechanical nanostructures. In September 2017, I started as Assistant Professor at the University of Twente.

Physics & Astronomy

# Bose-Einstein Condensates
# Condensates
# Condensation
# Gases
# Josephson Junctions
# Mirrors
# Photonics
# Photons

Faculty of Science and Technology (TNW), Adaptieve Quantum Optica (AQO)

My research team investigates physical phenomena at the interface between thermodynamics and quantum mechanics in optical and optomechanical systems. Our current research projects are:

Photon Bose-Einstein condensation
Optical spin glass simulation
Engineered thermal reservoirs

See our homepage for further details.

Key publications

Vretenar, M. (2022). Photon Bose-Einstein condensation in arbitrary potential landscapes. [PhD Thesis - Research UT, graduation UT, University of Twente]. University of Twente. https://doi.org/10.3990/1.9789036554671

Vretenar, M. , & Klärs, J. A. (2022). Mirror Surface Nanostructuring via Laser Direct Writing -- Characterization and Physical Origins. ArXiv.org. http://arxiv.org/abs/2211.05096v1

Puplauskis, M. , Toebes, C. , Vretenar, M. , Mattschas, C. U. , Sharoglazova, V. , & Klärs, J. A. (2022). Negatively coupled photon Bose-Einstein condensates. Poster session presented at 45th Annual Meeting NNV AMO 2022, Egmond aan Zee, Netherlands.

Sharoglazova, V. , Puplauskis, M. , Toebes, C. , Mattschas, C. U. , Vretenar, M. , & Klärs, J. A. (2022). Measuring the speed of photons in classically forbidden regions with condensation of light. Poster session presented at 45th Annual Meeting NNV AMO 2022, Egmond aan Zee, Netherlands.

Toebes, C. , Vretenar, M. , & Klärs, J. A. (2022). Dispersive and dissipative coupling of photon Bose-Einstein condensates. Poster session presented at NWO Physics@Veldhoven 2022.

Toebes, C. , Klärs, J. A. , & Vretenar, M. (2022). Tunable potential landscapes in optical microcavities using thermal expansion. Poster session presented at 45th Annual Meeting NNV AMO 2022, Egmond aan Zee, Netherlands.

Mattschas, C. U. , Vretenar, M. , & Klärs, J. A. (2022). Coherent networks of photon Bose-Einstein condensates. Poster session presented at 45th Annual Meeting NNV AMO 2022, Egmond aan Zee, Netherlands.

Sharoglazova, V. , Puplauskis, M. , Toebes, C. , Mattschas, C. U. , Vretenar, M., Kassenberg, B., Bissesar, S. , & Klärs, J. A. (2022). Condensation of light – from fundamental physics to optical computers. Poster session presented at MESA+ Meeting 2022, Enschede, Netherlands.

Toebes, C. , Vretenar, M. , & Klaers, J. (2022). Dispersive and dissipative coupling of photon Bose-Einstein condensates. Communications Physics, 5(1), [59]. https://doi.org/10.1038/s42005-022-00832-3

Öztürk, F. E., Lappe, T., Hellmann, G., Schmitt, J. , Klaers, J., Vewinger, F., Kroha, J., & Weitz, M. (2021). Observation of a non-hermitian phase transition in an optical quantum gas. Science, 372(6537), 88-91. https://doi.org/10.1126/science.abe9869

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