News
Estefani travels to Japan
Post-doctoral researcher, Dr. Estefani Marchiori travelled to Sendai, Japan to attend INTERMAG 2023 from Monday the 15th to Friday the 19th. INTERMAG is the premier international conference on all aspects of fundamental and applied magnetism. On Tuesday the 16th, Estefani gave a talk entitled, “Magnetic imaging of spin textures in a chiral magnet”, in a session on advances in magnetic characterization.
Fabricating SQUID-on-tips via Sputtering
On Tuesday the 9th, Applied Physics Letters published our paper entitled, Fabrication of Nb and MoGe SQUID-on-tip probes by magnetron sputtering as a featured article. In the paper, we demonstrate the fabrication of scanning superconducting quantum interference devices (SQUIDs) on the apex of sharp quartz scanning probes – known as SQUID-on-tip probes – using conventional magnetron sputtering. We produce and characterize SQUID-on-tips made of both Nb and MoGe with effective diameters ranging from 50 to 80 nm, magnetic flux noise down to 300 nΦ0/(Hz)1/2, and operating fields as high as 2.5 T. Compared to the SQUID-on-tip fabrication techniques used until now, including thermal evaporation and collimated sputtering, this simplified method facilitates experimentation with different materials, potentially expanding the functionality and operating conditions of these sensitive nanometer-scale scanning probes.
The research was led by Dr. Estefani Marchiori and carried out by Dr. Marchiori and former Ph.D. student — now post-doctoral researcher — Dr. Giulio Romagnoli. Dr. Kousik Bagani also contributed to the research.
Estefani at MonteSuper2023
From Monday the 17th to Friday the 21st, post-doctoral researcher Dr. Estefani Marchiori attended the International Meeting on Superconducting Quantum Materials and Nanodevices (MonteSuper2023), held in Budva, Montenegro. On Tuesday the 18th, Estefani gave an invited talk entitled, “Real-space imaging of magnetic phases in the chiral magnet Cu2OSeO3“. Topics of the conference included topological superconductivity, superconducting qubits, superconducting sensors, vortex imaging, and the interplay between magnetism and superconductivity.
Talk at MRS Meeting in San Francisco
On Wednesday the 12th, Prof. Poggio gave an invited talk at the Materials Research Society (MRS) Spring Meeting in San Francisco entitled, “Scanning Probe Microscopy of Stray Magnetic Field Produced by 2D Magnets”. The talk was part of symposium QM01 on “Novel Approaches to Manipulate and Detect 2D Magnetism in van der Waals Quantum and Topological Materials”, organized by Prof. Elton Santos of the University of Edinburgh.
6th SPM User Meeting
Prof. Poggio is hosting the 6th Scanning Probe Microscopy (SPM) User Meeting organized by Zurich Instruments here in Basel on May 25th. The event will take place in the Biozentrum on the campus of the University of Baasel and will consist of scientific talks, practical tutorial, and a poster session on SPM in the context of quantum sensing and microwave detection. Register here. Final program is here.
Weekend at the Zschokkehaus
On Friday the 10th, 13 members of the group made the trip to the university’s Zschokkehaus on the Gerschnialp above Engelberg, Switzerland. We stayed until Sunday morning and enjoyed some hiking in the snow, Eisstockschiessen, games, building an ingloo, movies, eating, and drinking. Thanks to Luca Forrer for the organization and to our host, Heinz Gubitzer, for the hospitality. Photos are here.
E-beam Lithography at the Tip of a Scanning Probe
On Friday the 3rd, AIP Advances published our paper entitled, Electron-beam lithography of nanostructures at the tips of scanning probe cantilevers. The paper describes a process for fabricating nanoscale metallic gate electrodes on scanning probe cantilevers, including on the irregular surface of protruding cantilever tips. The process includes a floating-layer technique to coat the cantilevers in an electron-beam resist. We demonstrate gate definition through both a lift-off process and an etching process. Importantly, the cantilevers retain their high force sensitivity after patterning. Our method allows for the fabrication of nanoscale devices on fragile scanning probes, extending their functionality as sensors.
The research was carried out by Ph.D. students Luca Forrer and Aurèle Kamber. Research scientist Dr. Floris Braakman led the team, which collaborated with Dr. Armin Knoll from IBM Zürich.
Here’s a video by Christel Moeller at the SNI on the work.
hBN Paper Published
On Monday the 27th, Nano Letters published our paper entitled, Mechanical Mode Imaging of a High-Q Hybrid hBN/Si3N4 Resonator. In the manuscript, we describe experiments characterizing the mechanical modes of a 2D drum resonator made of hBN suspended over a high-stress Si3N4 membrane. The measurements demonstrate hybridization between various modes of the hBN resonator and those of the Si3N4 membrane. This effect could be exploited to engineer hybrid drum/membrane modes that combine the low motional mass of 2D materials with the high quality factor of Si3N4 membranes for optomechanical or sensing applications.
The experiments were led by Ph.D. student David Jaeger and post-doctoral researcher Dr. Francesco Fogliano. Former Ph.D. student Dr. Thibaud Ruelle, Masters student Aris Lafranca, and research scientist Dr. Floris Braakman, who initially started this line of research in our group, also made major contributions.
Statistical Physics Course Starts
On Wednesday the 22nd, the Prof. Poggio’s Bachelor course ‘Statistical Physics for Nanoscientists’ started. The course is the last required physics course of the Nanoscience Bachelor curriculum here at the University of Basel. The course covers thermodynamics, statistical mechanics, and their applications to physics, chemistry, and biology. This is the first time that Prof. Poggio teaches this required course, after teaching ‘Physics II: Electrodynamics and Optics’ for 5 years.
Jonathan Marcks Visits
On Wednesday the 15th, Ph.D. student Jonathan Marcks of the Univeristy of Chicago visited the group. Jonathan works in the group of Prof. David Awschalom, who was Prof. Poggio’s Ph.D. advisor as well, and works on the quantum coherence of defect centers in diamond and other related materials. Jonathan gave a talk on his Ph.D. research in the afternoon, which was attended by members of the Poggio, Maletinsky, and Warburton Groups.
Prof. Andreas Heinrich Visits
On the 9th, Prof. Andreas Heinrich of the Center for Quantum Nanoscience in Seoul, South Korea visited our lab. His visit was part of the larger visit of our department’s Scientific Advisory Board. Prof. Heinrich toured the labs and discussed with group members on Thursday afternoon.
Estefani Speaks at Swiss Quantum Days
Between the 1st and 3rd, group members attended the Swiss Quantum Days workshop in Villars-sur-Ollon, Switzerland. The workshop continued the tradition of years of fruitful and inspiring NCCR QSIT General Meetings at Arosa, bringing together the community of researchers working on quantum research Switzerland. Post-doc Dr. Estefani Marchiori gave an invited talk on Thursday the 2nd entitled, “Real-space imaging of magnetic phases in the chiral magnet Cu2OSeO3“. Ph.D. student Daniel Jetter presented a poster on our work imaging 2D magnets using a SQUID-on-lever scanning probe. Prof. Poggio was also in attendance.
Masters Student Starts
On the 16th, Aris Lafranca started work on his Masters thesis in the group. Aris previously carried out a very successful Masters project in our group, in which he designed, built, and characterized a small room-temperature high-vacuum Michelson interferometer for mode imaging of nanomechanical resonators. He worked with Dr. Francesco Fogliano and Dr. Thibaud Ruelle. Now, Aris will rejoin Francesco and the nanomechanics team to investigate a number of nanomechanical resonators and the optomechanical properties.