Michel H. Devoret’s speech at the Nobel Prize banquet, 10 December 2025

Your Majesties, 
Your Royal Highnesses, 
Excellences, 
Dear Laureates, 
Ladies and gentlemen,

On behalf of Professor John Clarke, Professor John Martinis and myself, we wish to thank The Royal Swedish Academy of Sciences and the Nobel Foundation for the extraordinary honor of this prize. 

It is a mystery to me why my co-laureates, both native English speakers, have elected me to give this speech, considering my thick French accent. Let’s say this is an homage to the century-old French diplomatic tradition.

Our experimental work stemmed from a question asked by Professor Anthony Leggett: “Do macroscopic variables, like for instance the current in an electrical circuit, obey quantum mechanics?”

Not every physicist in the 1980’s agreed this question deserved years of complex experiments. But, as Tony said receiving himself the Nobel Prize 22 years ago for his work on the superfluidity of He3: “If there’s something in the conventional wisdom that you don’t understand, worry away at it, for as long as it takes, and don’t be deterred by the assurances of your fellow physicists that these questions are well understood”. 

In 2025, the year of 100th anniversary year of quantum mechanics, it is fair to say that some of the questions Tony was addressing to the foundations of quantum mechanics 40 years ago are still open. However, he clearly led the way to our experiment, which provided strong evidence that the macroscopic current in a tunnel Josephson junction indeed obeys quantum mechanics. This would prove to have practical consequences: we had realized the first artificial atoms, atoms to which macroscopic wires could be attached to make fast measurements and perform quantum operations. 

Thus, in addition to Tony Leggett, we owe our prestigious award to the many scientists, in many labs all over the world, who have taken these atoms and developed an entire field of research, not only in academia, but also in industry.