Dr. Simone Finizio

Simone Finizio is a postdoctoral fellow at the PolLux beamline of the Swiss Light Source since 2015. He obtained a bachelor degree with honorable mention in Physics Engineering in 2009 and a master's degree with honorable mention in Nuclear Engineering in 2011 at the Politecnico di Milano, in Italy. He then obtained his PhD in Physics in 2015, with the thesis "Field-free control of magnetism in nanostructured materials probed with high resolution X-ray microscopy" in the group of Prof. Mathias Kläui at the Johannes Gutenberg Universität Mainz, in Germany. After a short postdoctoral position in Prof. Kläui's group, Simone Finizio joined the microspectroscopy group at PSI within the framework of the EU Horizon 2020 "MagicSky" project, which ended successfully in 2018.

The institutional responsibilities of Simone Finizio are in the support of users performing magnetism and time-resolved investigations at the scanning-transmission X-ray microscope of the PolLux beamline of the Swiss Light Source.

Simone Finizio's scientific research has been focused on the imaging of sub-ns dynamical processes in magnetic materials with time-resolved X-ray magnetic microscopy, and in the development of techniques aimed at achieving that goal. Projects include the investigation of magnetic skyrmions and of their properties (until 2018 within the framework of the EU Horizon 2020 MagicSky project), the study of domain wall motion and spin wave processes, and the investigation of multiferroic materials. Furthermore, Simone Finizio is very active in the support of users investigating magnetic processes at the PolLux beamline of the Swiss Light Source, and in the development of numerous improvements for the beamline, ranging from design of RF setups, to the development of specific software solutions. A particular mention is given by the measurement automation scripts that he prepared, now being routinely utilized by the users preforming their measurements at PolLux. Finally, Simone Finizio has also a number of cooperations within and outside of PSI where he performs the lithographical fabrication of various samples. 

For an extensive overview we kindly refer you to our publication repository DORA.

Selected publications in chronological order.

Imaging three-dimensional magnetization dynamics with laminography, Claire Donnelly, Simone Finizio, Sebastian Gliga, Mirko Holler, Ales Hrabec, Michal Odstrcil, Sina Mayr, Valerio Scagnoli, Laura J. Heyderman, Manuel Guizar-Sicarios, and Jörg Raabe, Nature Nanotechnology volume 15, Article number: 356 (2020) 
Understanding and control of the dynamic response of magnetic materials with a three-dimensional magnetization distribution is important both fundamentally and for technological applications. From a fundamental point of view, the internal magnetic structure and dynamics in bulk materials still need to be mapped, including the dynamic properties of topological structures such as vortices, magnetic singularities or skyrmion lattices. From a technological point of view, the response of inductive materials to magnetic fields and spin-polarized currents is essential for magnetic sensors and data storage devices. Here, we demonstrate time-resolved magnetic laminography, a pump–probe technique, which offers access to the temporal evolution of a three-dimensional magnetic microdisc with nanoscale resolution, and with a synchrotron-limited temporal resolution of 70 ps. We image the dynamic response to a 500 MHz magnetic field of the complex three-dimensional magnetization in a two-phase bulk magnet with a lateral spatial resolution of 50 nm. This is achieved with a stroboscopic measurement consisting of eight time steps evenly spaced over 2 ns. These measurements map the spatial transition between domain wall motion and the dynamics of a uniform magnetic domain that is attributed to variations in the magnetization state across the phase boundary. Our technique, which probes three-dimensional magnetic structures with temporal resolution, enables the experimental investigation of functionalities arising from dynamic phenomena in bulk and three-dimensional patterned nanomagnets.

Deterministic field-free skyrmion nucleation at a nano-engineered injector device, Simone Finizio, Katharina Zeissler, Sebastian Wintz, Sina Mayr, Teresa Weßels, Alexandra J. Huxtable, Gavin Burnell, Christopher H. Marrows, and Jörg Raabe, Nano Letters 19, Article number: 7246 (2019) 
Magnetic skyrmions are topological solitons promising for applications as encoders for digital information. A number of different skyrmion-based memory devices have been recently proposed. In order to demonstrate a viable skyrmion-based memory device, it is necessary to reliably and reproducibly nucleate, displace, detect, and delete the magnetic skyrmions, possibly in the absence of external applied magnetic fields, which would needlessly complicate the device design. While the skyrmion displacement and detection have both been thoroughly investigated, much less attention has been dedicated to the study of the skyrmion nucleation process and its sub-nanosecond dynamics. In this study, we investigate the nucleation of magnetic skyrmions from a dedicated nanoengineered injector, demonstrating the reliable magnetic skyrmion nucleation at the remnant state. The sub-nanosecond dynamics of the skyrmion nucleation process were also investigated, allowing us to shine light on the physical processes driving the nucleation.

Dynamic imaging of the delay and tilt-free motion of Neel domains in perpendicularly magnetized superlattices, Simone Finizio, Sebastian Wintz, Katharina Zeissler, Alexandr V. Sadovnikov, Sina Mayr, Sergei A. Nikitov, Christopher H. Marrows, and Jörg Raabe, Nano Letters 19, Article number: 184 (2019)
We report on the time-resolved investigation of current- and field-induced domain wall motion in the flow regime in perpendicularly magnetized microwires exhibiting antisymmetric exchange interaction by means of scanning transmission X-ray microscopy with a 200 ps time step. The sub-ns time step of the dynamical images allowed us to observe the absence of incubation times for the motion of the domain wall within an uncertainty of 200 ps, together with indications for a negligible inertia of the domain wall. Furthermore, we observed that, for short current and magnetic field pulses, the magnetic domain walls do not exhibit a tilting during their motion, providing a mechanism for the fast, tilt-free, current-induced motion of magnetic domain walls.

Discrete Hall resistivity contribution from Neel skyrmions in multilayer nanodiscs, Katharina Zeissler, Simone Finizio, Kowsar Shahbazi, Jamie Massey, Fatma Al Ma'Mari, David M. Bracher, Armin Kleibert, Mark C. Rosamond, Edmund H. Linfield, Thomas A. Moore, Jörg Raabe, Gavin Burnell, and Christopher H. Marrows, Nature Nanotechnology 13, Article number: 1161 (2018) 
Magnetic skyrmions are knot-like quasiparticles. They are candidates for non-volatile data storage in which information is moved between fixed read and write terminals. The read-out operation of skyrmion-based spintronic devices will rely on the electrical detection of a single magnetic skyrmion within a nanostructure. Here we present Pt/Co/Ir nanodiscs that support skyrmions at room temperature. We measured the Hall resistivity and simultaneously imaged the spin texture using magnetic scanning transmission X-ray microscopy. The Hall resistivity is correlated to both the presence and size of the skyrmion. The size-dependent part matches the expected anomalous Hall signal when averaging the magnetization over the entire disc. We observed a resistivity contribution that only depends on the number and sign of skyrmion-like objects present in the disc. Each skyrmion gives rise to 22 ± 2 nΩ cm irrespective of its size. This contribution needs to be considered in all-electrical detection schemes applied to skyrmion-based devices. Not only the area of Néel skyrmions but also their number and sign contribute to their Hall resistivity.

Control of the gyration dynamics of magnetic vortices by the magnetoelastic effect, Simone Finizio, Sebastian Wintz, Eugenie Kirk, Anna K. Suszka. Sebastian Gliga, Phillip Wohlhüter, Katharina Zeissler, and Jörg Raabe, Physical Review B 96, Article number: 054438 (2017) 
The influence of a strain-induced uniaxial magnetoelastic anisotropy on the magnetic vortex core dynamics in microstructured magnetostrictive Co₄₀Fe₄₀B₂₀ elements was investigated with time-resolved scanning transmission x-ray microscopy. The measurements revealed a monotonically decreasing eigenfrequency of the vortex core gyration with the increasing magnetoelastic anisotropy, which follows closely the predictions from micromagnetic modeling.