For the duration of the SpinMelt ERC project, our team aimed to advance our understanding of unconventional superconductors, primarily through the development and application of advanced instrumentation. This effort led to progress, which was also directed by the insights we gained along the way, prompting deviations from our original trajectory and unexpected results.
A significant portion of our work was devoted to enhancing the STM's higher frequency capabilities – mainly in the regime of microseconds. We did this by introducing the cryogenic high-frequency amplifier. Developing the amplifier was a significant task that took several years, and input from several team members. In the end, the amplifier allowed us to delve deeper into pairing dynamics and explore the phenomenon of charge trapping in unconventional superconductors.
A first important discovery was the identification of a new quantum liquid state in a disordered superconductor. We found that in titanium nitride, electrons are paired even if the materials is not superconducting. This is special: in all conventional metals and insulators, single, non-paired electrons underpin the electronic properties.
A second important outcome stems from our work with scanning Josephson spectroscopy. We were the first to detect nanoscale inhomogeneity in superfluid within an iron-selenium-tellurium compound. This tells us what limits superconductivity in quantum materials.
There were many more findings and instrument developments, which we published along the way.
Throughout the project, we made our findings accessible, publishing in prominent (and less prominent) journals and presenting our work at conferences. We aimed to publish all papers in open access journals. We further deposited our data in repositories.
