Symmetry-enforced diffusive Langevin dynamics plus decoherence of high-momentum modes produces a universal momentum distribution that yields the parameter-free prediction C=3 for the coherence spreading constant ℓ²(t) = C ħ t / m.
Dynamical universality in a driven quantum fluid of light
1 Pith paper cite this work. Polarity classification is still indexing.
abstract
Universal scaling near phase transitions is one of the central ideas of physics, linking the growth of spatial correlations to the slowing down of dynamics. So far, direct experimental access to this critical behavior has remained largely confined to equilibrium many-body systems, and especially to static critical behavior. Here we probe how universality emerges in a driven quantum fluid of light formed by exciton--polaritons in a semiconductor microcavity. By probing the fluctuation-dominated disordered phase below the condensation threshold, we directly measure both the static growth of the correlation length $\xi$ and the dynamical slowing down of the relaxation time $\tau$. We find that these quantities obey the universal relation $\tau \propto \xi^{z}$ with dynamical exponent $z \approx 2$, revealing diffusive dynamics of a non-conserved order parameter. Our results extend the physics of critical dynamics from equilibrium matter to driven optical systems, bridging quantum condensates and lasers.
citation-role summary
citation-polarity summary
fields
cond-mat.quant-gas 1years
2026 1verdicts
CONDITIONAL 1roles
background 1polarities
background 1representative citing papers
citing papers explorer
-
Universal Speed Limit in a Far-from-Equilibrium Bose Gas: Symmetry and Dynamical Decoherence
Symmetry-enforced diffusive Langevin dynamics plus decoherence of high-momentum modes produces a universal momentum distribution that yields the parameter-free prediction C=3 for the coherence spreading constant ℓ²(t) = C ħ t / m.