Our research is on the fundamental aspects of quantum phenomena in light and matter, and has several potential applications in quantum information technology, quantum electronics and nanotechnology. Theoretical work also spans broader areas of physics. Below, a short introduction is given to the various research activities at the Division of Condensed Matter and Quantum Optics.

My field of research is condensed matter theory, and I am interested in low dimensional and strongly interacting systems, in particular topological phases of matter. In certain toplogical phases, particles with 'fractionalized quantum numbers' are possible. My research concentrates on the properties of these particles, how one can experimentally detect them, and utilize their properties.

Mathematical physics can mean many things. I and my students are working on the interplay between geometry and physics, in particular within general relativity theory, and within quantum information theory. Black holes, and the mysterious geometry of quantum state spaces, are very important to us.

We study quantum many-particle systems for which topology, entanglement and interactions play important roles. These include fractional quantum Hall states, geometrically frustrated magnets, Weyl semimetals and various instances of flat band models. A common feature in these systems is that their low-energy quasiparticles bear little or no resemblance to their electronic constituents.

The main focus of my research is on strongly correlated electron systems, and in particlar topological states of matter, the most prominent examples being the fractional Quantum Hall liquids.

Due to a significant technical progress and precise engineering, we are nowadays able to manipulate individual quantum systems, like single atoms, with a precision that has been unthinkable a few decades ago. Quantum technologies open many possibilities for applications, as for instance quantum computers that can solve problems intractable by classical computers, quantum-enhanced sensing and metrology, and quantum simulators that can improve our understanding of complex quantum phenomena. These applications are based on the special properties of quantum mechanics, like the exponential scaling of the Hilbert space, or the collective effects in entangled states.

My field of research is non-equilibrium statistical physics. Tools and techniques from this field can be used to address not only the properties of systems out-of-equilibrium (such as systems which are driven by temperature gradients), but even of computer networks or of systems of chemical reaction-networks. Most recently, we have investigated some properties of the latter. We have also looked at large deviation properties of noisy driven systems.

My research is theoretical and covers a broad range of topics like quantum optics, dynamics of quantum many-body systems, open quantum systems, and quantum phase transitions. More recently I have worked on ultracold atoms in optical lattices and how these systems can be used to simulate quantum magnetism and more exotic states of matter, non-equilibrium quantum phase transitions, chaos and how it relates to thermalization in quantum systems, and open quantum systems.

Semiconductor devices and non-linear processes can generate a wide spectrum of quantum states of light that can be employed in tasks of communication, simulation, and sensing. We use best tools and methods available to modern science to generate quantum light, harness its unique properties, and bring it closer to real-world application.

Our research is focused on thermodynamic, transport, and structural characterization of materials with novel electronic properties at low temperatures. Particular focus is on superconductivity, magnetism, and other systems with electronic phase transitions, where the effects of a magnetic field and field direction are central. The main experimental technique is nanocalorimetry, sometimes combined with concurrent x-ray diffraction.