On the 16th and 17th, the large collaborative project NCCR SPIN on “Spin qubits in Si” lead by members of our Department hosted a site visit. As part of the collaboration, members of the group attended talks and presented posters including Ph.D. students Liza Žaper, Andriani Vervelaki, Aurèle Kamber, and Luca Forrer. Prof. Poggio gave a summary talk.
On the 6th and 7th, Prof. Raffi Budakian of the University of Waterloo, Canada visited our group here at the Department of Physics. Raffi gave a talk on the afternoon of the 6th at our department’s Quantum & Nano Seminar entitled, “Novel Approaches in NanoMRI for Probing Atomic-Scale Material Structure”.
From the 30th to the 31st, Ph.D. student Daniel Jetter, post-doc Dr. Kousik Bagani, and Prof. Poggio attended the 3rd annual meeting of the “FIBsuperProbes” FET-Open collaboration between our group, the group of Dieter Kölle in Tübingen, the group of Armin Knoll at IBM Zürich, and the group of José María De Teresa in Zaragoza. Daniel gave a talk entitled, “Visualizing thickness-dependent spin texture in few layer Cr2Ge2Te6“. The meeting was organized by Prof. De Teresa in Zaragoza and featured a full day of talks, discussion, lab tours, and dinner. Thank you to José María for being an excellent host.
From the 24th to the 26th, Prof. Poggio attended the “Kryoelektronische Bauelemente (KRYO 2023)” Conference at the Seminaris Hotel in Bad Boll, Germany. The conference was organizing by Prof. Reinhold Kleiner and Prof. Dieter Kölle and covered recent developments in superconducting electronics and related techniques. Prof. Poggio gave a tutorial talk entitled, “Nanoscale magnetic field imaging for 2D materials.”
On Thursday the 21th, Ph.D. student David Jaeger defended his thesis, entitled, “Fiber-cavity optomechanics with hexagonal boron nitride drum resonators”, earning his doctorate in physics summa cum laude. The defense was chaired by Prof. Patrick Maletinsky with Prof. Eva Weig (TU Munich), Prof. Poggio, Prof. Richard Warburton, and Dr. Floris Braakman making up the committee.
After doing his Masters thesis in the Maletinsky group, David joined our lab as an intern in October 2017 and as a Ph.D. student in January 2018. Congratulations to Dr. Jaeger!
From the 14th to the 18th, 13 group members and friends traveled to Levanto, Italy for a long weekend at the beach. Levanto is a familiar getaway spot for Prof. Poggio, as his family has a house there and he has many friends in the town. The group enjoyed swimming, boating, kayaking, cliff jumping, hiking, sight seeing, eating, drinking, and of course relaxing by the sea. Thanks to all for an great time!
From the 6th to the 8th, Ph.D. students Lukas Schneider, Luca Forrer, and Prof. Poggio attended the Swiss Nanoscience Institute’s Annual Meeting, which was held for the first time in Meisterschwanden on the banks of lake Hallwil in the Canton Aargau, Switzerland. Lukas and Luca both gave talks on their research and Prof. Poggio hosted the proceedings as the Director of the SNI.
From the 4th to the 8th, Ph.D. student Andriani Vervelaki and post-doctoral researcher Dr. Kousik Bagani attended the Trends in MAGnetism 2023 conference in Rome, Italy. This was the third edition of this multidisciplinary forum on the advancements in magnetism with a focus on trending topics. Andriani presented a poster entitled, “Revealing the spin texture of 2D vdW Cr2Ge2Te6“, while Kousik presented a poster entitled, “Layer-dependent magnetization in 2D vdW Cr2Ge2Te6“.
From the 30th to September 1st, post-doctoral researcher Dr. Kousik Bagani attended the International Workshop on Superconductivity and Magnetism in Two Dimensional Films and Heterostructures in Bath, UK. Kousik gave an invited talk on the 31st in the session about 2D magnetism and spin dynamics. The talk was entitled, “Layer-dependent magnetization in 2D vdW Cr2Ge2Te6“.
On Wednesday the 30th, Prof. Poggio visited Royal Holloway University, outside of London, UK as the external referee on the Ph.D. thesis of Marius Hegedus. Congratulations to Marius on a successful ‘viva voce’ defense of his dissertation.
On Tuesday the 29th, Giulio hosted a barbecue on the department’s roof-top to to say farewell to his colleagues in the group and celebrate more than 6 years of working together. On Friday, Giulio starts a new position working at Zurich Instruments in Zürich, Switzerland. It was a pleasure working together and good luck on the new adventure, Giulio!
From the 29th to September 1st, research scientist Dr. Floris Braakman attended the Superconducting Qubits and Algorithms Conference in Munich, Germany.
From the 27th to September 1st, Ph.D. student Liza Žaper attended the 13th Joint European Magnetic Symposia (JEMS) in Madrid, Spain.
On Friday the 25th, we held our annual barbecue on the department’s roof-top with our colleagues from the Machine Shop, technicians, administrative staff, and friends. It was great to see former administrators Audrey Fischer and Barbara Kammermann there. Thanks to all who helped to organize and see you next year!
On the 21st and 22nd, post-doc Dr. Estefani Marchiori attended the “UK-Swiss Skyrmion Workshop” at the Ecole Polytechnique Fédérale de Lausanne (EPFL), organized by Prof. Chris Marrows (Leeds) and Prof. Dirk Grundler (EPFL). The workshop promoted future collaborations between scientists in the UK and Switzerland on magnetic skyrmions and related topics. Estefani gave a talk on the 22nd entitled, “Skyrmion imaging and manipulation at the surface of Cu2OSeO3“. Prof. Poggio attended on the 21st.
From the 6th to the 11th, Ph.D. students Andriani Vervelaki and Daniel Jetter attended the “4th PSI Condensed Matter Summer Camp” on “2D materials: insights and opportunities at large scale facilities” at the Lyceum Alpinum in Zuoz, Switzerland. The summer camp had the goal to provide a forum for leading scientists to meet and discuss the fundamental aspects and open questions of current scientific interest. It follows a more than 20-year tradition of holding condensed matter schools at the Lyceum Alpinum that provides a lively and informal environment for scientific discussions. In this edition, the following topics were included: superconductivity in the 2D limit, charge and spin density wave instabilities in 2D maetrials, topological transport and electronic structure in two dimensions, twisted bilayers and freestanding heterostructures, ferromagnets in two dimensions, 2D Magnetism and spin liquids, novel methods to probe materials in two dimensions, and devices based on 2D materials. Andriani presented a poster entitled, “Revealing layer-dependent magnetization and spin texture in 2D Cr2Ge2Te6“.
From the 31st of July to the 2nd, Prof. Poggio attended a workshop on “Quantum sensing and fundamental physics with levitated mechanical systems” hosted at the European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*) in Trento, Italy. The workshop aimed to bring together theorists and experimentalists working in the field of levitated nano/micromechanical systems, using various platforms (optical, electrical, magnetic) and in related fields in order to discuss the most recent results and exchange ideas in order to explore new opportunities in quantum sensing and fundamental physics. Prof. Poggio gave a talk on the 2nd entitled, “Scanning SQUID-on-tip microscopy of 2D and chiral magnetism”.
On Tuesday the 27th, Ph.D. student Hinrich Mattiat defended his thesis, entitled, “Nanowire magnetic force microscopy”, earning his doctorate in physics summa cum laude. The defense was chaired by Prof. Andrea Hofmann with Prof. Poggio, Prof. Richard Warburton, and Dr. Thomas Mühl (IFW Dresden) making up the committee.
Hinrich joined the group in January of 2018, after doing his Masters thesis in the Degen group (ETHZ). Having seen his work at ETHZ, Prof. Poggio convinced Hinrich to bring his talents to Basel, where he worked on developing nanowire-based magnetic force microscopy and was the first to apply the technique to investigate 2D materials. Congratulations to Dr. Mattiat!
On the 25th, we had our 7th annual BBQ at the Birsköpfli park along the river Rhine. Group members, alumni — including Dr. Michele Montinaro and Dr. Andrea Mehlin — and friends spent the afternoon enjoying the weather, eating, drinking, and cooling off in the river. Thanks to all for a good time. See you next year!
From the 8th to the 10th, Prof. Poggio attended the 8th Conference on Spin Polarized Scanning Tunneling Microscopy and Nanoscale Magnetic Imaging (SP-STM-8 and NMI-1) on the invitation of Prof. Jay Gupta. The program highlighted recent SP-STM work, but also featured contributions from leading experts in other nanoscale magnetic imaging techniques such as Lorentz TEM, diamond NV-center magnetometry, x-ray holography and MFM/MExFM. These techniques provide unique and complementary insights into a range of areas including quantum information systems, quantum matter, spintronics, and biological systems. The program included both experimental and theoretical developments, aswell as the development of new systems and techniques. Prof. Poggio gave a talk on the 8th entitled, “Scanning SQUID-on-tip microscopy of 2D and chiral magnetism”. A video of the talk is available here.
On the 25th, Prof. Poggio hosted the 6th Scanning Probe Microscopy (SPM) User Meeting organized by Zurich Instruments. The event took place in the Biozentrum on the campus of the University of Baasel and will consisted of scientific talks, practical tutorial, and a poster session on SPM in the context of quantum sensing and microwave detection. Both Prof. Poggio and Ph.D. student Liza Zaper gave a talk at the workshop entitled, “Imaging weak magnetic field patterns on the nanometer-scale” and “Characterizing nanomagnets used for silicon spin qubit operation”, respectively.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.