Collision complexes

Collisions between ultracold molecules lead to loss mediated by formation of complexes. Our new theory quantifies the lifetime of these complexes and indicates their loss could be to due photo-excitation.
Phys. Rev. Lett. 123, 123402 (2019)

Interaction engineering

Interactions between molecules can be controlled using microwaves. We show how this gives access to strong resonant dipolar interactions.
Phys. Rev. Lett. 125, 063401 (2020)


Experiments on ultracold KRb molecules quantitatively confirm our theory of collision complex lifetimes and photo-excitation rates.
Nature Physics 16, 1132 (2020)


Microwaves can be used to engineer repulsive interactions between molecules that can prevent losses while maintaining large elastic cross sections, key to cooling molecules to high phase-space density.
Phys. Rev. Lett. 121, 163401 (2018)


Dr. Tijs Karman

  • 2021-
    Assistant professor, Radboud University
  • 2018-2021
    Post-doctoral fellow, ITAMP, Harvard NWO Rubicon grant and ITAMP fellowship
  • 2017-2018
    Post-doc, Durham University, with Jeremy Hutson
  • 2013-2017
    Ph.D., Radboud University, with Gerrit Groenenboom

Computer codes available

Open source computer code is available through gitlab. This currently contains our code for the computation of the density of states and photo-excitation rate of molecule-molecule collision complexes.


Publications in the Theoretical Chemistry database
Publications in Google Scholar

B.Sc. and M.Sc. thesis projects

Please send me a message if you are interested in opportunities for a bachelor's or master's research project in chemistry or physics.