Ab initio Light-Matter Group

Our interest lies at the interface of established research areas – the uncharted territory in between the beaten paths.

We interweave 3 domains to a unique approach at the forefront of applied computational materials science:

(i) development of theoretical tools to describe the self-consistent and non-perturbative interaction between (quantized) electromagnetic fields and realistic matter from first principles

(ii) advancing green chemistry via polaritonic chemistry, plasmonic catalysis, and chiral polaritonics

(iii) predicting novel quantum-impurity systems, exploring quantum scrambling, and developing near-term quantum algorithmic

Find more details in the research and publications tab or contact us directly via the people section. We are usually equipped with towels, but always welcoming and open minded.

news

Apr 23, 2026	New paper out! Have you ever wondered how a laser-pointer works if you shrink it down to nanometer scales? No worries, we’ve got you covered. The smallest lasers consist of a nanometer-sized cavity, made from nanoparticles, with only a handful of molecules in between that serve as gain medium. Together with Kai and Kimmo, we applied our novel BBGKY-HEOM approach (informed from first principles) and discovered something unexpected: the vibrational properties of these molecules can cause unusual resonances in the laser output. These resonances depend on how strongly the molecules are pumped, their vibrational structure, and the number of molecules. The relative strength of resonant features in the lasing output increases with the number of molecules and can not be explained within the mean-field approximation – a feature that might be useful to identify the precise number of participating molecules. Once again, we find that making things smaller certainly doesn’t make it simpler. (Müller et al., 2026)
Mar 27, 2026	New paper out! Dating can be tough, even between impurity molecules and organic crystals. Here, we play the role of a matchmaker and identify new couples that could build a bright future as quantum light-matter interface (Öhman et al., 2026)

Apr 23, 2026

New paper out! Have you ever wondered how a laser-pointer works if you shrink it down to nanometer scales? No worries, we’ve got you covered. The smallest lasers consist of a nanometer-sized cavity, made from nanoparticles, with only a handful of molecules in between that serve as gain medium. Together with Kai and Kimmo, we applied our novel BBGKY-HEOM approach (informed from first principles) and discovered something unexpected: the vibrational properties of these molecules can cause unusual resonances in the laser output. These resonances depend on how strongly the molecules are pumped, their vibrational structure, and the number of molecules. The relative strength of resonant features in the lasing output increases with the number of molecules and can not be explained within the mean-field approximation – a feature that might be useful to identify the precise number of participating molecules. Once again, we find that making things smaller certainly doesn’t make it simpler. (Müller et al., 2026)

Mar 27, 2026

New paper out! Dating can be tough, even between impurity molecules and organic crystals. Here, we play the role of a matchmaker and identify new couples that could build a bright future as quantum light-matter interface (Öhman et al., 2026)