We are performing research in quantum information science and in quantum many-body theory, topics that we regard as being closely intertwined with each other.

Quantum information science
We ask what information processing tasks are possible using single quantum systems as carriers of information. We think about the mathematical-theoretical foundations of quantum information, specifically about the theory of entanglement. We ask how properties can be reliably recovered and how features can be learned. Here, ideas of compressed sensing and of machine learning come into play. And think about notions of topological quantum information processing and error correction.

• Quantum information theory
• Quantum system identification
• Topological quantum error correction
• Quantum communication
• Quantum thermodynamics
• Complexity of complex quantum systems
• Quantum machine learning

Quantum many-body theory
A main emphasis of our theoretical research is in condensed matter theory, exploring static properties of quantum many-body systems, their efficient numerical simulation, as well as their quantum dynamics in non-equilibrium. Methods of tensor networks play a special role here. They are often a hammer to be used in our approach. We are also involved in identifying quantum optical realizations of such ideas, specifically using light modes or cold atoms in optical lattices.

• Tensor network methods and topological order
• Non-equilibrium physics
• Many-body localization
• Dissipative complex quantum systems
• Open quantum systems
• Cold atoms in optical lattices
• Optical systems