Postdoctoral Positions in Experimental Nanophotonics and Quantum Optics

The research group of Professor Maiken H. Mikkelsen at the Niels Bohr Institute (NBI), University of Copenhagen, invites applications for two Postdoctoral Researcher positions in experimental nanophotonics and quantum optics.

Professor Mikkelsen’s group studies how light and matter interact when light is confined to nanometre-scale volumes. Using plasmonic nanocavities — metallic nanogaps fabricated deterministically around a chosen emitter — the group reaches a regime far beyond the reach of conventional optical cavities: Purcell factors above 10,000, single-photon emission at telecom wavelengths with lifetimes of tens of picoseconds at room temperature, and second-harmonic generation enhanced more than ten-million-fold in materials with no bulk nonlinearity. In this regime, light–matter behaviour appears that was not previously thought possible, and the group’s experiments are increasingly directed at the nonlinear and ultrafast optics it opens up. Experiments combine nanofabrication, single-photon and photon-correlation spectroscopy, cryogenic magneto-optics and ultrafast pump–probe optics. The group has recently relocated from Duke University to NBI, supported by a DKK 35 million RECRUIT award from the Novo Nordisk Foundation, and is establishing a laboratory in NBI’s new building. Postdocs joining now will help build the laboratory and shape its first experiments. Recent work:  https://mikkelsenphotonics.com .

The positions span three axes of control over light–matter interaction; the balance between them will depend on the candidates:

Spatial structure — shaping the vacuum around an emitter and concentrating the field for nonlinear optics, with examples including Purcell tensors, the nanophotonic Lamb shift, harmonic generation in nanoscale volumes, and forbidden and two-photon transitions opened by field gradients.

Emitter number — cavity QED with exactly one, two or several emitters, including the crossover from room-temperature to cryogenic strong coupling, collective emission, and multi-exciton emission that outruns Auger recombination.

Temporal control — ultrafast and time-resolved experiments on single nanocavities, including single-nanocavity pump–probe spectroscopy, optically dressed states in quantum materials embedded in nanogaps, and time-varying cavities.

We seek outstanding, creative, and highly motivated experimentalists with a PhD in physics, chemistry, materials science, electrical engineering, or a closely related discipline, and a strong background in one or more of: nanophotonics or cavity QED; quantum optics and photon-correlation measurements; cryogenic spectroscopy of solid-state emitters or two-dimensional materials; ultrafast optical spectroscopy; nanofabrication. Candidates are encouraged to propose directions of their own within this scope; the programme will be shaped by the people who join.

The successful candidates will carry out experimental research, help set up the new laboratory, including a 1.7 K cryostat with a vector magnet, a tunable femtosecond laser system and single-photon confocal spectroscopy, publish and present results, and participate in the supervision of students. The positions may also include collaboration with national and international research partners and other academic duties as required. The group fabricates its cavities in the NBI cleanroom and at DTU Nanolab, Denmark's national nanofabrication centre.

Further information on the Department at https://nbi.ku.dk/english/. Informal inquiries are welcome and can be made to Professor Maiken H. Mikkelsen, maiken.mikkelsen@nbi.ku.dk.

The positions are for three years, starting as soon as possible, with flexible start dates into 2027.

The University wishes our staff to reflect the diversity of society and thus welcomes applications from all qualified candidates regardless of personal background.