The Royal Swedish Academy of Sciences today announced that the 2025 Nobel Prize in Physics is being awarded to three scientists for their work in quantum mechanics. The official citation reads: “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit”. The 2025 Nobel prize will be shared equally by:
John Clarke, University of California, Berkeley, USA,
Michel H. Devoret, Yale University and the University of California, Santa Barbara, USA
and
John M. Martinis, University of California, Santa Barbara, USA
A major question in physics is the maximum size of a system that can demonstrate quantum mechanical effects. This year’s Nobel Prize laureates conducted experiments with an electrical circuit in which they demonstrated both quantum mechanical tunnelling and quantised energy levels in a system big enough to be held in the hand.
For more information, see the 2025 announcement on the Nobel Prize webpage.