Anne L’Huillier and Pierre Agostini, Nobel Prize winner in physics and masters of infinitesimal time

2023-10-07 18:30:01
Anne L’Huillier, at Lund University (Sweden), October 3, 2023. OLA TORKELSSON/AFP Pierre Agostini, at home in Paris, October 5, 2023. JOEL SAGET/AFP

“It will remain a great moment, a strong memory”appreciates Anne L’Huillier, co-winner of the 2023 Nobel Prize in Physics, covered in flowers received from her students, from her neighbors in Lund, near Malmö (Sweden), or from the president of the university where she is a professor. “He took the train to get to campus and give them to me!” » The day after the prize was announced, on October 4, she agreed to sacrifice an hour of her atomic physics course for third-year engineering students to speak about Nobel. “The amphitheater was fuller than usual”she notes mischievously.

His co-recipient, Pierre Agostini, retired from the Atomic Energy Commission (CEA) and professor emeritus at Ohio State University, received fewer flowers but was also very surprised. His daughter warned him late in the morning of October 3, after reading the news on the Internet. The Nobel jury will only contact him verbally in the afternoon.

With the Austro-Hungarian Ferenc Krausz, these three Nobel winners were nicknamed by certain media “the paparazzi of the infinitely small”. Not a bad find. « Paparazzi » because, in fact, they have developed devices capable of capturing fleeting and intimate moments. ” Infinitely small “, because the alcove whose secrets he reveals is truly microscopic. The stars are some of the most modest particles there are, the electrons, which around the nuclei form the atoms, allow the bonds of these atoms into molecules, or transport the current in conductive materials.

Every photographer knows that to capture moving scenes you need a short exposure time, otherwise you risk having a blurry photo. To capture the dance of electrons, this time is really very short. On the order of an attosecond, or a billionth of a billionth of a second. A time so short that there are approximately as many attoseconds in a second as there are seconds since the birth of the Universe.

CEA recruiters

How did the two French winners become attosecond photographers? It seems that you first have to be good at… math. “I didn’t like chemistry, so I took the maths-physics option in preparatory classes”remembers Anne L’Huillier, 65, who entered ENS Fontenay in 1977, where she passed the maths aggregation. “She impressed us with this specialty”, remembers Pierre Agostini, 82 years old, who was in the same group as her at the CEA in the 1980s-1990s. He, born in Tunis, and gone to Sarthe at the age of 15 to attend the La Flèche military high school for his baccalaureate, also preferred this subject. “But, at university, I was advised to study physics and optics”he explains about his student years in Marseille, where his family had settled. “I then turned to physics because I loved the classes of future Nobel Prize winners Claude Cohen-Tannoudji [1997] and Serge Haroche [2012] in atomic physics »indicates for her part Anne L’Huillier.

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