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Updated: Oct 20, 2025

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
Published on: August 18, 2017
Observation of fragmentation of a spinor Bose-Einstein condensate
Bertrand Evrard1, An Qu1, Jean Dalibard1
1Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL University, Sorbonne Université, 75005 Paris, France.
Abstract:
Weakly interacting Bose gases usually form Bose-Einstein condensates in which most particles occupy the same single-particle state. However, when this state cannot realize a continuous symmetry of the many-body Hamiltonian, a fragmented condensate exhibiting the expected symmetry may emerge. Here, we produced a three-fragment condensate for a mesoscopic spin-1 gas of about 100 atoms, with anti-ferromagnetic interactions and vanishing collective spin. Using a spin-resolved detection approaching single-atom resolution, we show that the reconstructed state is close to the expected many-body ground state, whereas one-body observables are the same as for a completely mixed state. Our results highlight how the interplay between symmetry and interactions generates entanglement in a mesoscopic quantum system.
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