Electronic, optical and magnetic properties of low-dimensional systems

The search for new superconducting materials for widespread use remains a cornerstone of condensed matter physics and materials science. Cuprate superconductors, copper oxides with record critical temperatures at ambient pressure, often inspire this quest. Recent theoretical work suggests an AgF2 allotrope could surpass this 30-year record. Our ISC-CNR unit initiated this concept [1] and, via a MURPRIN project, partners with POLIMI to study silver fluorides using advanced x-ray spectroscopies. Resonant Inelastic X-ray Scattering (RIXS) excels at determining exchange interaction and electronic correlation energies, vital for unconventional superconductivity. RIXS has proven successful for cuprates and other 3d transition metal oxides [2,3], and also for 5d transition metals like iridates [4]. For silver, a 4d metal, RIXS offers insights into electronic and magnetic properties, crucial for discovering novel quantum phenomena, refining theories, and guiding new material synthesis. Critically, no high-resolution RIXS instrument currently exists for Ag compounds. We propose collaborating with Dr. Hlynur Gretarsson at P01 of Petra III-DESY (Hamburg, D) to upgrade their RIXS end-station [5] for unprecedented measurements. This facility is uniquely adaptable to our ambitious aims. Our RIXS instrumentation and experimental expertise, combined with German partners' knowledge and our theoretical skills, will maximize experimental