Kjetil Børkje

Faculty of Technology, Natural Sciences and Maritime Sciences
Department of Science and Industry systems
Campus Kongsberg (5395)
I am a theoretical physicist and I am interested in how quantum physics can manifest itself on large scales and how that can be useful.


  • Education
    I teach physics and math courses for teacher students and engineering students at the University of South-Eastern Norway.
  • Research
    I belong to the research group on Quantum Technology. My primary research interest is the control and manipulation of artificial systems in the quantum regime. During the past decade, I have worked extensively within the field of quantum optomechanics, which deals with the interaction of electromagnetic radiation and mechanical oscillators. I am particularly interested to find out how large mechanical systems can be forced to behave in ways unexplainable by classical physics, but also how mechanical systems can be used to manipulate the properties of light or microwaves at the quantum level. For further details, see the link to the list of publications below. 

    I am a participant in the project QuaSeRT (Optomechanical quantum sensors at room temperature), which is an international research project funded by the Horizon2020 Cofund-program QuantERA.
  • Outreach
    - In the fall of 2017, I gave a popular lecture in Norwegian about quantum technology which can be viewed here.
    - Popular science article on quantum computers in the monthly magazine Aftenposten Innsikt, February 2020, available here
    - Popular science talk at Tekna breakfast seminar on quantum technology, March 2020, available here.



  • 2018-               Professor, University of South-Eastern Norway
  • 2017-2018       Professor, University College of Southeast Norway
  • 2017-2017       Associate professor, University College of Southeast Norway
  • 2015-2016       Associate professor, Royal Norwegian Naval Academy
  • 2014-2015       Postdoc, University of Oslo
  • 2012-2014       Postdoc, Niels Bohr Institute
  • 2009-2012       Postdoc, Yale University


  • 2008     PhD, physics, Norwegian University of Science and Technology
  • 2003     Siv.ing. (MSc), physics and mathematics, Norwegian University of Science and Technology


Selected publications

  • Single-photon optomechanics,
    A. Nunnenkamp, K. Børkje, S. M. Girvin, Phys. Rev. Lett. 107, 063602 (2011)
  • Proposal for entangling remote micromechanical oscillators via optical measurements,
    K. Børkje, A. Nunnenkamp, S. M. Girvin, Phys. Rev. Lett. 107, 123601 (2011)
  • Cooling and squeezing via quadratic optomechanical coupling,
    A. Nunnenkamp, K. Børkje, J. G. E. Harris, S. M. Girvin, Phys. Rev. A 82, 021806 (2010)
  • Signatures of nonlinear cavity optomechanics in the weak coupling regime,
    K. Børkje, A. Nunnenkamp, J. D. Teufel, S. M. Girvin, Phys. Rev. Lett. 111, 053603 (2013)
  • Ground state cooling of mechanical motion in the unresolved sideband regime by use of optomechanically induced transparency,
    T. Ojanen, K. Børkje, Phys. Rev. A 90, 013824 (2014) 
  • Heterodyne photodetection measurements on cavity optomechanical systems: Interpretation of sideband asymmetry and limits to a classical explanation,
    K. Børkje, Phys. Rev. A 94, 043816 (2016)

See more at Google Scholar