Implementation of Polarization-Based Truncated SU(1,1) Interferometer in Hot Rb Vapor

摘要

In this manuscript, we discuss the performance of a recently demonstrated polarization-based truncated SU(1,1)interferometer1 which can potentially generate polarization-entangled twin beams for applications in quantumcommunications or in quantum metrology as an interferometer with enhanced phase sensitivity. Using theintensity-squeezed twin beams generated via four-wave mixing (FWM) in hot Rubidium vapor, we report thedetection of nearly -2 dB of noise reduction below the shot-noise in the joint-quadrature measurements in suchinterferometer. We also used this setup to con rms the non-classical nature of quantum correlations betweenthe twin beams with an inseparability parameter I = 1:32 0:04 that falls below the classical limit of 2. One ofthe important advantages of the proposed interferometer is its better rejection of common-mode, technical, andenvironmental noises due to its intrinsic symmetry, which allows for squeezing and entanglement measurementsat wide spectrum of detection frequencies from as low as 200 Hz (limited by 1=f electronic noise) to up to a fewMHz (limited by the photodetector gain bandwidth).