Research activities

The main goal of research area A “Quantum-correlated many-body systems” is the development of a comprehensive understanding and control of interacting, correlated few- and many-body systems. Our initial focus will be on developing new tools for manipulating, detecting, and characterizing quantum correlations in systems ranging from tens to tens of thousands of particles. We will develop an understanding of and ultimately the ability to exploit open systems dynamics, which play a crucial role in many applications. Once we have mastered these quantum many-body systems, we will investigate their equilibrium and non-equilibrium properties in 1D, 2D, and 3D geometries and explore applications, including the quantum simulation of quantum magnetism, novel quantum phases, supersolids, and Haldane insulators, and the study of the quantum-to-classical transition and quantum non-locality in progressively larger systems.

The main objective of research area B “Quantum metrology for tests of fundamental physics” is the design of quantum-correlated few- and many-body states to enhance the performance of useful measurement instruments, such as clocks and matter-wave interferometers, and to use their improved resolution and sensitivity to explore physics beyond the Standard Model (SM). We will demonstrate the operation of atom interferometers up to 16 dB below the standard quantum limit (SQL), and matter-wave interferometers with wave packet separations of metres that are probed for seconds, and demonstrate their usefulness for inertial sensing and in atomic clocks. We will build multi-ensemble optical clocks with inaccuracies better than 10^-18 and instabilities approaching 10^-17 after 1 s integration time, employing correlations to improve the signal-to-noise ratio and to suppress systematic effects. By extending the quantum atom optics toolbox to more exotic systems, such as (anti-)protons, nuclei, and molecules, we will be able to make highly accurate frequency comparisons between novel systems. Accurate spectroscopy of such systems will allow us to improve current bounds on violations of CPT symmetry, on violations of local Lorentz invariance (LLI), and on a possible variation of the fine-structure constant α or the electron-to-proton mass ratio µ = m_e/m_p by at least two orders of magnitude, complementing and possibly clarifying astrophysical observations. Furthermore, we will develop a quantum version of the equivalence principle and explore possible non-trivial effects of gravity on extended quantum objects.

The collaboration between the two RAs to achieve DQ-mat’s overarching vision is implemented through so-called Topical Groups (TGs) in which several projects will jointly address selected topics from different angles. The TGs act as central communication and collaboration hubs within DQ-mat: project scientists in a TG will meet on a regular basis to discuss common scientific questions, develop novel ideas at the interface of metrology and many-body quantum systems, and foster the transfer of successful concepts from well-established to novel and possibly more involved systems.