Riccardo Arpaia, Quantum Device Physics

Abstract: Superconductivity represents one of the most enigmatic phenomena in condensed matter physics. Of particular intrigue is the microscopic mechanism underlying superconductivity in cuprate High critical Temperature Superconductors (HTS), where the critical temperature can reach -140°C at ambient pressure. Here, this unconventional phase is the product of a very intricate interplay between the constituent electrons, including their spin, charge, orbital and lattice configuration. Disentangling the various correlated degrees of freedom contributing to the physics of these materials is a big challenge.

In this lecture, I will provide an overview of the novel perspectives used in the last decade to tackle this challenge, drawing upon the advances both in the growth of HTS films and in the development of new experimental techniques. On one hand, external manipulations (e.g., strain induced by substrate in thin film, confinement effects in nanostructures, mechanical strain on single crystals) have been used to modify the ground state of HTS compounds, with the aim to simplify the hierarchy between local orders and their connection to superconductivity. On the other hand, transport and Resonant X-ray Scattering techniques have been combined, to scrutinize how macroscopic transport properties correlate with local electronic configuration changes.

Throughout this overview, I will highlight key results, discuss challenges overcome, and offer insights into our future work. The long term-goal is to reveal the ‘knobs’ that can be tuned, potentially paving the way for the design of new materials that bring us closer to achieving room-temperature superconductivity.

Coffee will be served after the lecture.