Mesoscopic quantum tunneling effect in superconducting circuits

• Francesco De Stefano

One of the most promising routes towards achieving quantum advantage is based on superconducting quantum circuits. The operation of these systems is based on the robustness of the Josephson effect, which endows the circuit with a lossless nonlinearity and enables quantum-mechanical tunneling on length scales far larger than the atomic ones. From the pioneering works that have led to the 2025 Nobel Prize, we will briefly explore how far the field has advanced, highlighting the crucial role of the charge-phase duality and presenting one of the most widely used superconducting circuits - the transmon qubit - which holds promise both for quantum computing and for quantum metrological applications.

Dicussion

Super Eddington accretion in Supermassive Black Holes

• Riccardo Caleno

New astrophysical observations reveal surprisingly massive black holes at very high redshift, pushing standard growth models to their limits. In this scenario, a promising pathway is given by super-Eddington accretion, that could provide a natural explanation for how supermassive black holes grew so fast in the early Universe. In this talk I will outline the current state of the art, in both observations and theoretical models, showing also some results from cosmological hydrodynamical simulations, and finally how this kind of mechanism could affect the population of supermassive black holes.

Discussion