Who: Alessio Vegliante, Pre-doctoral Researcher, Nanoimaging
Place: nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
Date: Monday, 19 September 2022, 11:00
Engineering ?-magnetism in carbon-based nanostructures
Magnetic carbon-based materials and nanostructures have recently emerged as potential building blocks for spintronics and quantum computation. They offer, in fact, several advantages compared to transition metals, since their low spin-orbit coupling and hyperfine interaction result in longer spin coherence times, more delocalized magnetic moments and long-range spin interactions.
While magnetism is missing among the properties of ideal graphene, an intrinsic spin polarization can develop in some graphene nanostructures with well-defined shapes exhibiting an open-shell character, i.e., possessing one or more unpaired ?-electrons. The high reactivity of these systems makes their synthesis and characterization particularly challenging. Recently, however, the advances of on-surface synthesis performed on metal substrates in ultra-high vacuum environments have allowed to fabricate open-shell carbon nanostructures with atomic precision. At the same time, the growth on metal substrates has the advantage of enabling the characterization of these nanostructures by means of surface science techniques, like scanning tunneling microscopy and spectroscopy.
Here we will show our results on the characterization of magnetic interactions in different spin-hosting carbon nanostructures with progressively higher number of unpaired ?-electrons. Firstly, we will report our investigation of the intramolecular spin coupling in individual organic radicals on metal substrates. Then, we will present a more complex system, a cyclic structure exhibiting fingerprints of collective spin states. Finally, we will briefly describe our ongoing attempts at growing more extended networks with the aim of exploring the emergence of carbon magnetism in two-dimensional systems.