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MA: Fachverband Magnetismus
MA 49: Magnetic Imaging, Information Technology, and Sensors
MA 49.3: Vortrag
Donnerstag, 12. März 2026, 15:30–15:45, POT/0112
SQUID-on-lever scanning probe for magnetic imaging with sub-100-nm spatial resolution — Timur Weber2, •Daniel Jetter1, Martino Pogio1, and Dieter Kölle2 — 1Department of Physics, University of Basel, 4056 Basel, CH — 2Physikalisches Institut, University of Tübingen, 72076 Tübingen, Germany
Scanning superconducting quantum interference device (SQUID) microscopy is a magnetic imaging technique combining high field sensitivity with nanometer-scale spatial resolution. We demonstrate a scanning probe that combines the magnetic and thermal imaging with the tip-sample distance control and topographic contrast of a non-contact atomic force microscope. We pattern the nanometer-scale SQUID, including its weak-link Josephson junctions, via neon or helium focused ion beam milling on a niobium coated cantilever. These SQUID-on-lever probes overcome many of the limitations of existing devices, achieving spatial resolution better than 100 nm, magnetic flux sensitivity of 0.3 µ Φ0 / √Hz, operation in magnetic fields up to about 0.5 T and the incorporation of a third Josephson junction for shifting its phase. Its advanced functionality, high spatial resolution, and the ease of use of a cantilever-based scanning probe, extends the applicability of scanning SQUID microscopy to a wide range of magnetic, superconducting, and quantum Hall systems. We demonstrate magnetic imaging of skyrmions at the surface of bulk Cu2OSeO3. Analysis of the SQUID’s point spread function yields a full-width-half-maximum of 71 nm that allows to image modulated magnetization patterns with a period of 65 nm.
Keywords: Superconductivity; SQUID; Scanning probe microscopy; Magnetic imaging