The world's smallest 'lauburu'

In recent years, magnetic interactions in nanographenes have been a major focus in quantum materials research. A new study published in National Science Review takes this exploration further by investigating how the unpaired π-electrons of nanographenes interact with magnetic metal atoms (iron and cobalt). This novel approach provides new fresh insights into π-d exchange coupling, a key mechanism for spintronics and quantum computing.

The study, led by researchers from Shanghai Jiao Tong University and Hefei National Laboratory, used scanning tunneling microscopy and spectroscopy to reveal a magnetic exchange interaction of 9 meV (Fe) and 5 meV (Co). These findings were further supported by quantum chemistry calculations by Ricardo Ortiz and Thomas Frederiksen, researchers from the Donostia International Physics Center (DIPC) and Ikerbasque, the Basque Foundation for Science.

By demonstrating how nanographenes can couple with metal centers to enhance quantum magnetism, this research opens new pathways for engineering metal-organic frameworks with tunable magnetic properties. The results mark an important step towards tailor-made molecular magnets, with implications for next-generation quantum technologies and nanoscale electronics.

Beyond its scientific significance, the study has an unexpected local connection: one of the observed molecules takes the shape of a lauburu, the traditional Basque symbol. Given the precision of the imaging techniques, this is likely to be the smallest lauburu ever observed—a fitting coincidence for a discovery involving DIPC, right in the heart of the Basque Country!