Publications by authors named "Goncalo Catarina"
Unlocking the potential of topological order in many-body spin systems has been a key goal in quantum materials research. Despite extensive efforts, the quest for a versatile platform enabling site-selective spin manipulation, essential for tuning and probing diverse topological phases, has persisted. Here we utilize on-surface synthesis to construct spin-1/2 alternating-exchange Heisenberg chains by covalently linking Clar's goblets-nanographenes each hosting two antiferromagnetically coupled spins.
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- The research focuses on open-shell nanographenes, emphasizing the significance of considering both spin and orbital degrees of freedom in low-energy excitations, rather than just spins.
- The study highlights nitrogen-doped triangulenes as a key example, utilizing advanced computational methods like density-functional theory and the Hubbard model.
- Findings suggest a complex interaction between orbital and spin features, challenging the traditional spin-only framework and suggesting new directions for future research in nanographenes.
Article Synopsis
- Phenalenyl (CH) is a type of nanographene that features a unique open-shell structure with spin-1/2 properties, revealing interesting electrical behavior when studied through techniques like STM-IETS.
- Researchers have discovered that the exchange interactions in phenalenyl dimers can be adjusted by changing the angle between the two molecules, which can lead to different electronic properties.
- The study employs various theoretical approaches, including density functional theory, to explore ways to manipulate twisting in these dimers, potentially enabling control over magnetic couplings in carbon-based structures.
Magnetic Excitations in Ferromagnetically Coupled Spin-1 Nanographenes.
Angew Chem Int Ed Engl
December 2024
In the pursuit of high-spin building blocks for the formation of covalently bonded 1D or 2D materials with controlled magnetic interactions, -electron magnetism offers an ideal framework to engineer ferromagnetic interactions between nanographenes. As a first step in this direction, we explore the spin properties of ferromagnetically coupled triangulenes-triangular nanographenes with spin . By combining in-solution synthesis of rationally designed molecular precursors with on-surface synthesis, we successfully achieve covalently bonded triangulene dimers and trimers on Au(111).
View Article and Find Full Text PDFFractionalization is a phenomenon in which strong interactions in a quantum system drive the emergence of excitations with quantum numbers that are absent in the building blocks. Outstanding examples are excitations with charge e/3 in the fractional quantum Hall effect, solitons in one-dimensional conducting polymers and Majorana states in topological superconductors. Fractionalization is also predicted to manifest itself in low-dimensional quantum magnets, such as one-dimensional antiferromagnetic S = 1 chains.
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