Complete the experimental study of superfluidity in non-equilibrium condensates

Complete the experimental study of superfluidity in driven-dissipative condensates with spontaneously broken U(1) symmetry, including a quantitative determination of their superfluid and normal fractions.

Background

Driven-dissipative condensates possess complex-valued collective-mode dispersions, including a potentially diffusive Goldstone mode. This makes the conventional Landau criterion difficult to apply and prevents a straightforward quantitative extraction of superfluid and normal fractions from defect-scattering measurements. The review therefore identifies a complete experimental investigation of superfluidity in this class of condensates as unresolved.

References

In spite of the pioneering development reported in, a complete experimental study of this configuration is still lacking.

— Collective excitations of driven-dissipative quantum fluids of light  (2609.40110 - Bramati et al., 30 Sep 2026) in Section 6.2, subsection “Superfluidity in driven-dissipative condensates”