Quantum-SOPHA was an ANR project dedicated to the quantum dynamics of interacting bosons in one dimension. Running from September 2021 to August 2025, it brought together two complementary analogue simulators: ultracold atoms confined on an atom chip and a propagating quantum fluid of light.
Interactions and correlations are enhanced in one dimension because particles cannot simply move around one another. Quantum-SOPHA used this distinctive regime to investigate the Lieb–Liniger model, a central description of interacting one-dimensional bosons, both close to equilibrium and after a strong perturbation.
The atomic platform implements the model with tightly confined ultracold atoms and hard-wall boundaries. The photonic platform uses the propagation of light through a nonlinear medium as an effective time evolution and naturally supports a ring geometry with periodic boundaries. Comparing the two makes it possible to benchmark results when exact theoretical predictions are difficult to obtain.
The project focused on two connected directions:
At LKB, the project strengthened our one-dimensional photon-fluid experiments and their connection to atomic quantum gases, quantum hydrodynamics and nonequilibrium many-body physics.
Visit the Quantum-SOPHA project website or read the official ANR project summary.