The curious history of how quantum mechanics came to be ‘seen’ in an electrical circuit

Quantum mechanics is usually described as the science of the very small — of electrons, atoms, and photons that behave in ways that defy the rules of everyday experience. Yet one of the most striking results of modern physics is that this quantum behaviour doesn’t vanish abruptly when systems become large. Instead, it continues to show itself in the behaviour of groups of particles doing something together. Over the years, physicists have learnt how to engineer these groups, measure them, and even control them to perform specific tasks.

The 2025 physics Nobel Prize has been awarded to John Clarke, Michel Devoret, and John Martinis for showing in their experiments that quantum tunnelling — a phenomenon in which a particle passes through an energy barrier instead of having to climb over