nanowires; experimental condensed matter physics; nano-magnetism; SQUIDs; micro- and nanomechanics; nuclear magnetic resonance; magnetic resonance force microscopy
Marchiori E., Ceccarelli L., Rossi N., Romagnoli G., Herrmann J., Besse J.-C., Krinner S., Wallraff A., Poggio M. (2022), Magnetic imaging of superconducting qubit devices with scanning SQUID-on-tip, in Applied Physics Letters
, 121(5), 052601-052601.
Philipp S., Gross B., Reginka M., Merkel M., Claus M. M., Sulliger M., Ehresmann A., Poggio M. (2021), Magnetic hysteresis of individual Janus particles with hemispherical exchange biased caps, in Applied Physics Letters
, 119(22), 222406-222406.
Gross B., Philipp S., Josten E., Leliaert J., Wetterskog E., Bergström L., Poggio M. (2021), Magnetic anisotropy of individual maghemite mesocrystals, in Physical Review B
, 103(1), 014402-014402.
Geirhos Korbinian, Gross Boris, Szigeti Bertalan G., Mehlin Andrea, Philipp Simon, White Jonathan S., Cubitt Robert, Widmann Sebastian, Ghara Somnath, Lunkenheimer Peter, Tsurkan Vladimir, Neuber Erik, Ivaneyko Dmytro, Milde Peter, Eng Lukas M., Leonov Andrey O., Bordács Sándor, Poggio Martino, Kézsmárki István (2020), Macroscopic manifestation of domain-wall magnetism and magnetoelectric effect in a Néel-type skyrmion host, in npj Quantum Materials
, 5(1), 44-44.
Gross B., Philipp S., Geirhos K., Mehlin A., Bordács S., Tsurkan V., Leonov A., Kézsmárki I., Poggio M. (2020), Stability of Néel-type skyrmion lattice against oblique magnetic fields in GaV4S8 and GaV4Se8, in Physical Review B
, 102(10), 104407-104407.
Mehlin A., Gross B., Wyss M., Schefer T., Tütüncüoglu G., Heimbach F., Fontcuberta i Morral A., Grundler D., Poggio M. (2018), Observation of end-vortex nucleation in individual ferromagnetic nanotubes, in Physical Review B
, (13), 134422-134422.
Vasyukov D., Ceccarelli L., Wyss M., Gross B., Schwarb A., Mehlin A., Rossi N., Tütüncüoglu G., Heimbach F., Zamani R. R., Kovács A., Fontcuberta i Morral A., Grundler D., Poggio M. (2018), Imaging Stray Magnetic Field of Individual Ferromagnetic Nanotubes, in Nano Letters
, (2), 964-970.
Wyss M., Mehlin A., Gross B., Buchter A., Farhan A., Buzzi M., Kleibert A., Tütüncüoglu G., Heimbach F., Fontcuberta i Morral A., Grundler D., Poggio M. (2017), Imaging magnetic vortex configurations in ferromagnetic nanotubes, in Physical Review B
, (2), 024423-024423.
Rossi Nicola, Braakman Floris R., Cadeddu Davide, Vasyukov Denis, Tütüncüoglu Gözde, Fontcuberta i Morral Anna, Poggio Martino (2016), Vectorial scanning force microscopy using a nanowire sensor, in Nature Nanotechnology
, (2), 150-155.
Gross B., Weber D. P., Rüffer D., Buchter A., Heimbach F., Fontcuberta i Morral A., Grundler D., Poggio M. (2016), Dynamic cantilever magnetometry of individual CoFeB nanotubes, in Physical Review B
, (6), 064409-064409.
Buchter A., Wölbing R., Wyss M., Kieler O. F., Weimann T., Kohlmann J., Zorin A. B., Rüffer D., Matteini F., Tütüncüoglu G., Heimbach F., Kleibert A., Fontcuberta i Morral A., Grundler D., Kleiner R., Koelle D., Poggio M. (2015), Magnetization reversal of an individual exchange-biased permalloy nanotube, in Physical Review B
, (21), 214432-214432.
The study of nanometer-scale magnetism is a vibrant sub-field of condensed matter physics concerned principally with magnetic phenomena in low-dimensional systems -- phenomena that are often not observable in macroscopic systems. Its relevance to a variety of applications including precision sensing, high-density information storage and processing, and sensitive scanning probe techniques make the subject of particular technological interest. In this document, we propose to leverage our laboratory's expertise in nanometer-scale magnetometry in the pursuit of two distinct lines of experimental research. In the first, we aim to use sensitive cantilever and SQUID magnetometry to study the skyrmion phase in nanometer-scale structures. In the second, we intend to use the unique capability of magnetic resonance force microscopy (MRFM) to measure nuclear magnetic resonance (NMR) from nanometer-scale samples to determine the strength of the spin-orbit interaction (SOI) in semiconductor nanowires (NWs). Both projects represent applications of nanometer-scale magnetometry aimed at elucidating poorly-understood physical phenomena, which either have not been -- or cannot be -- measured by other means.Measuring Skyrmions in Nanostructures (Project A): Since their initial observation in 2009, magnetic skyrmions have attracted an intense and broad interest among physicists. These topologically nontrivial spin structures are stable or metastable configurations that arise due to Dzyaloshinskii-Moriya interactions and appear in B20 materials with a helical ground state. Skyrmions are considered promising as carriers of information in high-density magnetic media due to a number of favorable properties, including their nanometer-scale size and the ultra-low electrical current density required to move them. Here we propose to investigate skyrmions in nanometer-scale structures, in which the reduced dimensionality stabilizes the skyrmion phase, significantly extending its range in both temperature and magnetic field. Such a stabilization and the mechanism behind it is particularly important if any practical applications of skyrmions are to be realized.Measuring the Spin-orbit Interaction in Nanowires (Project B): Semiconductor NWs with strong SOI have attracted a great deal of recent interest due to the various topologically non-trivial electronic states that they are predicted to support. These states include helical states and Majorana bound states around topological defects. In order to create and identify such states, measurements of the SOI in the relevant NWs must be made. We aim to make the first of these measurements by realizing a recent proposal by group of Prof. Daniel Loss. Their theory predicts that the nuclear spin relaxation rate in a ballistic NW with Rashba and SOI will show pronounced signatures, which depend on the strength of the SOI. We intend to use our demonstrated ability to do nanometer-scale NMR on semiconductor NWs to measure these signatures.The main applicant, Prof. Martino Poggio, was promoted to tenured associate professor in the Physics Department at the University of Basel in January 2014. After nearly 6 years in Basel, he has an established research group working on nanomechanics, nanomagnetism, and nanoMRI. His group currently consists of 3 post-doctoral researchers and 6 Ph.D. students. He is a winner of a 2013 ERC Starting Grant and has has active collaborations around the world including with Prof. Erik Bakkers (Eindhoven/Delft), Prof. Song Jin (Wisconsin), Prof. Dirk Grundler (TU München), Prof. Dieter Koelle (Tübingen), and Prof. Pietro Carretta (Pavia). Within Switzerland he is part of the Swiss Nanoscience Institute and the NCCR Quantum Science and Technology and has active collaborations with Prof. Anna Fontcuberta i Morral (EPFL) and Prof. Christian Degen (ETHZ). He collaborates with various colleagues in Basel, including Prof. Richard Warburton, Prof. Daniel Loss, and Prof. Stefan Willitsch.