The WMI opens its doors for the public audience from 10:00 to 17:00. All are invited to learn more about our cutting-edge research in quantum physics. For the detailed program of the institute, please see https://www.wmi.badw.de/detail-pages/tdot2026.
For general information, please visit https://forschungscampus-garching.de/.
Speaker: Dr. Daniele De Bernardis, CNR-INO / LENS
Title: Electrostatics-induced breakdown of the integer quantum Hall effect in cavity QED
Time: Wednesday, July 29th, 2026, 14:15 h
Speaker: Prof. Dr. Carlos Gonzalez-Ballestero, TU Wien
Title: Passive state transfer between qubits coupled to a waveguide
Time: Monday, July 27th, 2026, 15:00 h
Researchers at the Walther-Meißner-Institut have shown that cavity electromechanical devices can serve as ultrasensitive sensors for materials research, enabling the detection of individual magnetic flux vortices in a superconducting nanostructure. Cavity electromechanical systems convert minute mechanical displacements into microwave signals and are among the most sensitive motion detectors available today. While they are primarily developed as platforms for quantum technologies, practical sensing applications remain rare.
Using a suspended 30-micrometer-long aluminum nanostring, the researchers exploited attonewton-scale force sensitivity to observe the entry of individual magnetic flux quanta into a superconductor. Such vortices are of considerable interest because they can introduce loss and noise in superconducting devices. By monitoring tiny changes in the nanostring's mechanical resonance frequency, the team resolved signatures of single vortex-entry events. The work demonstrates a new sensing application of cavity electromechanics and provides a powerful tool for studying the formation and dynamics of magnetic flux vortices in superconducting nanostructures.
The WMI participated in the summer party of the Bavarian Academy of Sciences and Humanities in the Botanical Garden in Munich. Vera Bader and Matthias Opel performed experiments at low temperatures with liquid nitrogen. Matthias discussed the thermal expansion of gases and solids. Vera demonstrated the low viscosity of nitrogen in comparison to water, utilizing a prototypical Bavarian felt hat. Finally, they explained the Meißner-Ochsenfeld effect and showed the levitation of a high-Tc (YBa2Cu3O7−δ) superconductor above a permanent magnet using the superconducting WMI racetrack.
Silicon-vacancy spins in diamond are promising candidates for building phononic quantum devices, where quantized vibrational modes—rather than photons—are used as quantum information carriers. In current devices, however, coherence times are still too short to realistically implement such a scheme. Based on a protocol recently developed at WMI, a team of researchers from Harvard University has demonstrated that the coherence times of silicon-vacancy spins can be enhanced by continuously driving them with a strong acoustic wave. In their study published in Nature Physics, the authors demonstrated that this experimental technique not only prolongs the lifetime of the quantum superposition, but also achieves record-high spin rotation frequencies—a crucial control tool for manipulating spins on incredibly short timescales.
