Circuits Josephson : des phénomènes quantiques macroscopiques aux atomes artificiels

Michel Devoret retraces the experimental discovery of macroscopic quantum tunnelling and quantised energy levels in superconducting electrical circuits. The lecture explains how Josephson circuits became controllable quantum systems and how these experiments opened a route from observing quantum behaviour in a macroscopic device to engineering artificial atoms.

He connects this foundational work, recognised by the 2025 Nobel Prize in Physics shared with John Clarke and John Martinis, to the development of superconducting qubits and present approaches to quantum computing. The account links the original physical phenomena to the subsequent effort to build useful quantum processors from electrical circuits.