An ultra-compact low temperature scanning probe microscope for magnetic fields above 30 T

Construction of a cryogenic dual scanner magnetic force microscope equipped with piezoresistive cantilever

We present a low-temperature magnetic force microscope (MFM) incorporating a piezoresistive cantilever and a dual-range scanner for experiments across a wide temperature range from cryogenic levels to room temperature. The piezoresistor-based MFM eliminates the need for optical readjustment, typically required due to thermal expansion at varying temperatures, thereby providing a more stable and precise measurement environment. The integration of a dual scanner system expands the versatility of scanning operations, enabling accurate sample positioning for detailed exploration of magnetic and superconducting properties under diverse thermal conditions. To demonstrate the capabilities of our MFM, we show detailed imaging of Fe3GaTe2, a van der Waals ferromagnet, and Yb0.7Y0.3CuAs2, a ferromagnetic cluster glass material. These studies demonstrate the potential of our MFM in revealing intricate details of magnetic domain dynamics and contribute to our understanding of materials exhibiting the anomalous Hall effect as well as superconducting phenomena.

A new view on the origin of zero-bias anomalies of Co atoms atop noble metal surfaces

Many-body phenomena are paramount in physics. In condensed matter, their hallmark is considerable on a wide range of material characteristics spanning electronic, magnetic, thermodynamic and transport properties. They potentially imprint non-trivial signatures in spectroscopic measurements, such as those assigned to Kondo, excitonic and polaronic features, whose emergence depends on the involved degrees of freedom. Here, we address systematically zero-bias anomalies detected by scanning tunneling spectroscopy on Co atoms deposited on Cu, Ag and Au(111) substrates, which remarkably are almost identical to those obtained from first-principles. These features originate from gaped spin-excitations induced by a finite magnetic anisotropy energy, in contrast to the usual widespread interpretation relating them to Kondo resonances. Resting on relativistic time-dependent density functional and many-body perturbation theories, we furthermore unveil a new many-body feature, the spinaron, resulting from the interaction of electrons and spin-excitations localizing electronic states in a well defined energy.