Assistant Professor (fixed-term) in Experimental Nanophotonics and Quantum Optics

The Niels Bohr Institute (NBI), University of Copenhagen, invites applications for a fixed-term Assistant Professor position in experimental nanophotonics and quantum optics, in the group of Professor Maiken H. Mikkelsen. The position is for four years, open from as soon as possible; a later start in 2027 can be negotiated.

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 second-order 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. Recent work: https://mikkelsenphotonics.com .

The Assistant Professor will lead an independent research direction within the group’s programme on light–matter interaction in nanocavities. Directions of particular interest include:

• Cavity QED with few emitters — strong coupling with exactly one, two or several quantum emitters in deterministically fabricated nanogaps, the crossover from room-temperature to cryogenic strong coupling, collective emission, and quantum light generation from nanocavity-coupled emitters

• Quantum and two-dimensional materials in nanogaps — out-of-plane excitations (interlayer excitons, dark excitons, trions) coupled to the vertical field of a nanogap at cryogenic temperatures and in vector magnetic fields; optically dressed states of 2D semiconductors and magnets driven inside a nanogap and read out by single-cavity ultrafast spectroscopy

• Ultrafast and nonlinear nanophotonics — time-resolved experiments on single nanocavities, including single-nanocavity pump–probe spectroscopy, harmonic generation in nanoscale volumes, time-varying cavities, and forbidden and two-photon transitions opened by field gradients

Candidates are expected to define their own experimental programme within this scope, and proposals that cut across these directions are welcome.

This is a leadership position for an early-career scientist ready for independence. The Assistant Professor will be the senior scientist in the group alongside Professor Mikkelsen, with day-to-day responsibility for one research direction and its students. The successful candidate will take scientific ownership of the group's new cryogenic and ultrafast facilities, including a 1.7 K cryostat with a vector magnet and a tunable femtosecond laser system, co-supervise PhD and master's students, and develop their own funding portfolio, with active support from the group and the institute. They will be supported in applying as principal investigator for Danish and European early-career grants, and the position includes a dedicated budget line for a student and consumables. The group fabricates its cavities in the NBI cleanroom and at DTU Nanolab, Denmark's national nanofabrication centre.

We seek an outstanding experimentalist, typically three to seven years after the PhD, with a strong publication record, demonstrated independence, and hands-on expertise in several of: nanophotonics, cavity QED or plasmonics; quantum optics and photon-correlation measurements; cryogenic optical and magneto-optical spectroscopy; ultrafast pump–probe spectroscopy; nanofabrication. Expertise in the exfoliation, transfer, assembly and encapsulation of van der Waals heterostructures, including gated devices, is an asset. Experience supervising students and an interest in teaching are expected. The group is simultaneously recruiting postdoctoral researchers; candidates may apply to both positions.

The position is a fixed-term appointment of four years, funded by external research grants, and is not tenure-track. The objective is that the successful candidate concludes the appointment with an established research direction, an independent funding record, and a strong case for a permanent position at the University of Copenhagen or elsewhere.

The assistant professor’s duties will primarily include research, including obligations with regard to publication/scientific communication and research-based teaching with associated examination obligations within quantum optics and photonics. To a limited extent this may also include performance of other duties.