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/.
Researchers at WMI have proposed a new type of laser called a bosonic avalanche laser, where a stream of bosonic particles drives a chain reaction resembling an avalanche. Remarkably, random particle arrivals can generate a highly regular laser output, a phenomenon known as coherence resonance, usually associated with excitable systems such as neurons. Even under extremely weak signals, where quantum fluctuations are large, the device maintains surprisingly regular behavior. By converting single particles into amplified, easily detectable pulses, the system could enable ultra-sensitive quantum sensors. The team also outlines a superconducting-circuit implementation and demonstrates how the technology could function as a single-photon detector for microwave-frequency quantum signals.
Matthias Opel was invited to a MINT Career Information Day, organized by the Humboldt Academy of Science and Engineering (HASE) at the Humboldt-Gymnasium Vaterstetten, Germany. Being one of 22 speakers, he presented his daily life as a senior scientist in low temperature physics in four individual, 45-min sessions with 10 high school students each. Finally, he performed a 30-min show with liquid nitrogen for the general audience in the main auditorium and demonstrated the levitation of a high-Tc (YBa2Cu3O7−δ) superconductor above a permanent magnet.
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.
