Katharina Starts her Ph.D.

On the 1st, Katharina Kress started her Ph.D. in our group. Katharina received her Bachelor of Science in Physics in 2022 from the University of Basel. After completing a Master project in our group in February of 2024, she decided to pursue her Masters thesis with us starting the following March. She worked on designing and fabricating Nb 3-junction SQUIDs on planar cantilevers and characterizing them as scanning probes. After writing an excellent thesis and defending it in January of 2025, she decided to pursue her Ph.D. in our group. Welcome!

End of FIBsuperProbes

After four and a half years, on the 31st, our consortium FIBsuperProbes officially came to and end. As a European Union-funded Horizon 2020 research project, it focused on developing nanometer-scale superconducting quantum interference devices (SQUIDs) on cantilever scanning probes. To accomplish this task, researchers in the consortium used focused-ion-beam (FIB) techniques, producing sensors with unprecedented size, functionality, and sensitivity, directly on custom-designed cantilevers. The scanning probes developed during the project hold immense potential for scanning applications such as high-resolution imaging of stray magnetic fields in van-der-Waals 2D magnets. Use of these probes in various research groups and even their commercialization is on-going.

Thanks to all the students, post-docs, technicians, and scientists involved in the project over the years. The collaboration between the groups of Dr. Armin Knoll (IBM Research Zürich), Prof. Jose Maria De Teresa (CSIC Zaragoza), Prof. Dieter Kölle (University of Tübingen), and our own group in Basel was both a pleasure and a great success. We look forward to working together soon in follow-up projects!

Thanks also, of course, to the European Union for the funding and our host institutions for providing the necessary support.

Final FIBsuperProbes Workshop

On the 25th and 26th, the FIBsuperProbes consortium, which we coordinate, came together for a vibrant and productive workshop at the CSIC office in Brussels. Over two days, researchers, collaborators, and industry representatives shared their latest progress on SQUID-on-cantilever devices and explored exciting applications in high-resolution magnetic imaging. The event featured engaging talks, insightful discussions, and valuable networking opportunities. We were especially pleased to welcome external guests from companies working in areas such as thin film technology and AFM cantilever fabrication, whose perspectives added depth to the conversations. A program can be found here.

Thank you to all participants for their contributions and to Research Scientist Dr. Boris Groß, who organized the very successful event.

New Cryostat Installed

The week of the 17th, group members and a technician from the company BlueFors installed a new LD400 cryostat in the lab. The successful installation opens new possibilites for experiments at extremely low temperatures, down to 10 mK. Thanks especially to the Swiss National Science Foundation, the Swiss Nanoscience Institute, and the University of Basel for funding this important piece of equipment. Thanks also to Research Scientist Dr. Floris Braakman, who led the efforts to win funding, dealt with the design and purchase, and coordinated the installation.

News & Views by Paritosh in Nature

On the 5th, a News & Views article by research scientist Dr. Paritosh Karnatak and emeritus Prof. Christian Schönenberger entitled, ‘Unconventional’ superconductivity probed in twisted graphene, appeared in Nature. The piece highlights two research articles reporting on measurements of kinetic inductance in twisted bilayer and trilayer graphene, respectively.

Nano Letters publishes paper on micromagnets for spin qubits

On the 22nd, Nano Letters published our paper entitled, Simulation and measurement of stray fields for the manipulation of spin qubits in one- and two-dimensional arrays. By means of micromagnetic simulations and scanning superconducting quantum interference device (SQUID) microscopy (SSM), we show that the polycrystallinity of the magnet and nonuniform magnetization significantly impact the stray field and corresponding qubit properties. The random orientation of the crystal axis in polycrystalline Co magnets alters the qubit frequencies by up to 0.5 GHz, compromising single qubit addressability and single gate fidelities. We map the stray field of Fe micromagnets with an applied magnetic field of up to 500 mT, finding field gradients above 1 mT/nm. The measured gradients and the lower magnetocrystalline anisotropy of Fe demonstrate the advantage of using Fe instead of Co as magnets in spin qubit devices. These properties of Fe also enabled us to design a 2D arrangement of nanomagnets for driving spin qubits distributed on a 2D lattice.

The work represents a collaboration between our group and researchers at IBM Research Zürich. Ph.D. student Michele Aldeghi led the work and carried out the simulations and fabricated the samples under the supervision of Dr. Gian Salis and Dr. Rolf Allenspach at IBM. Our part of the study involved imaging the magnetic stray fields of the micromagnets via SSM. Ph.D. students Andriani Vervelaki and Daniel Jetter and former post-doctoral researcher Dr. Kousik Bagani carried out the work and analyzed the data with support from research scientist Dr. Floris Braakman. This included fabricating SQUID-on-lever probes, running low-temperature scanning probe measurements, and interpreting the data in the unusual regime of very high stray field.

Loris Starts as Ph.D.

On the 6th, Loris Durante started work as a Ph.D. student in the group. Loris received his Bachelor of Science in 2022 and his Master of Science in 2024 both in Physics from the University of Basel. He carried out both his Master project and thesis in our group on the fabrication, characterization, and optimization of SQUID-on-tip sensors for operation below 1 K. After successfully defending his work, he decided to join the group as a Ph.D. student. Welcome!