In our joint research project, we will test quantum physics using an extremely heavy particle (~ atomic mass units, 50um diameter) using a novel experimental platform, and we will use this platform for ultra-sensitive force sensing.

Our particle is a superconducting ball confined in a magnetic trap. We aim to cool the ball’s center-of-mass motion to the ground state, then to prepare the motion in a quantum state. To achieve this, we will carefully probe and control the particle using superconducting quantum circuits. These superconducting quantum circuits offer an extensive toolbox for preparing, manipulating and measuring the particle’s motion with high efficiency.

The unique combination of a massive particle with ultrahigh coherence and state-of-the-art superconducting quantum circuits also makes our platform an excellent force sensor. This has the potential to open new avenues for dark matter detection, gravitational wave detection and fundamental tests of quantum gravity.


Recent Publications


Westphal, T., Hepach, H., Pfaff, J., and Aspelmeyer, M.: Measurement of gravitational coupling between millimetre-sized masses. Nature591, 225–228 (2021).

Magrini, L., Rosenzweig, P., Bach, C., Deutschmann-Olek, A., Hofer, S.G., Hong, S., Kiesel, N., Kugi, A., and Aspelmeyer, M.: Real-time optimal quantum control of mechanical motion at room temperature. Nature595, 373 (2021).

Navau, C., Minniberger, S., Trupke, M., and Sanchez, A.: Levitation of superconducting microrings for quantum magnetomechanics. Physical Review B103, 174436 (2021).

Delic, U., Reisenbauer, M., Dare, K., Grass, D., Vuletic, V.,  Kiesel, N., Kugi, A., and Aspelmeyer, M.: Cooling of a levitated nanoparticle to the motional quantum ground state. Science367, 892 (2020).

Hofer, J., and Aspelmeyer, M.: Analytic solutions to the Maxwell–London equations and levitation force for a superconducting sphere in a quadrupole field. Physica Scripta94, 12558 (2019).



Luschmann, T., Schmidt, P., Deppe, F., Marx, A., Sanchez, A., Gross, R., and Huebl, H.: Mechanical frequency control in inductively coupled electromechanical systems. Under review (2021).

Fedorov, K.G., Renger, M., Pogorzalek, S., Di Candia, R., Chen, Q., Nojiri, Y., Inomata, K., Nakamura, Y., Partanen, M., Marx, A., R. Gross, and Deppe, F.: Experimental quantum teleportation of propagating microwaves. Under review(2021).

Schmidt, P., T.-Amawi, M., Pogorzalek, S., Deppe, F., Marx, A., Gross, R., and Huebl, H.: Sideband-resolved resonator electromechanics on the single-photon level based on a nonlinear Josephson inductance. Communication Physics3, 1 (2020).