Enhancing Sensitivity via Superradiant Phase Transition in Continuous-Variable Bosonic Systems

Precision measurement has been a driving force in physics, from the uncertainty principle to modern quantum sensing, enabling the exploration of phenomena across microscopic and cosmic scales. We demonstrate significant sensitivity enhancement in a two-mode continuous-variable bosonic system by leveraging a first-order superradiant phase transition (SPT) induced by parametric nonlinearity. The SPT causes the divergence of quantum fluctuations, enhancing the sensitivity. We characterize the sensitivity through a dimensionless quantum Fisher information. Compared to a continuous-variable system without SPT, the sensitivity near the critical point exhibits an enhancement of three orders of magnitude. The universal theory represents a truly macroscopic quantum detection approach that can be demonstrated in general quantum systems and applied to a variety of nonlinear models.