Active Quantum State Purification and Nonlinear-Order Filtering via Longitudinal Light Drag in Four-Wave Mixing
In electromagnetically induced transparency (EIT) media, the generation of highly pure quantum squeezed states via four-wave mixing (FWM) is fundamentally limited by co-propagating higher-order nonlinearities. These processes shear the quantum phase space and couple anti-squeezed noise into the measurement axis, destro...