Claude Cohen-Tannoudji’s legacy spans groundbreaking cooling of atoms, the students he trained, influential textbooks, and his crucial role in sustaining international scientific collaboration.

The French physicist and Nobel laureate Claude Cohen-Tannoudji died in Paris at 93 on October 22, 2026, as confirmed by the Kastler Brossel Laboratory.

Cohen-Tannoudji shared the 1997 Nobel Prize in Physics for developing laser cooling and trapping of atoms, a breakthrough that transformed quantum measurements.

His group achieved cooling to a few nanokelvin, advancing atomic clocks and atom interferometry.

His research centered on using laser beams to slow and confine atoms, pioneering Sisyphus cooling and redefining quantum optics.

Together with colleagues, he helped surpass the Doppler limit, enabling Sisyphus cooling of atoms to nanokelvin temperatures.

In 1997, he shared the Nobel Prize with Steven Chu and William D. Phillips for cooling and trapping atoms with laser light, enabling precise quantum measurements.

In 2001, he co-authored a Physical Review Letters paper with C.S. Unnikrishnan describing a Bose-Einstein condensate in a thin helium gas.

Cohen-Tannoudji visited India multiple times, notably participating in an Indo-French workshop in Bangalore in 1999, delivering the first Homi J. Bhabha Lecture in Mumbai, and speaking in New Delhi.

He was renowned for his generosity and collaboration, mentoring younger physicists like Alain Aspect and fostering cross-cultural scientific dialogues, including Israeli-Arab collaborations.

He maintained strong ties with Israel, supporting Israeli research, visiting the Weizmann Institute repeatedly, and promoting France-Israel scientific cooperation.

Beyond science, he educated generations as a professor at the Collège de France for over 30 years and co-authored influential quantum mechanics textbooks with Bernard Diu and Franck Laloë.