Low-frequency vacuum squeezing via polarization self-rotation in Rb vapor

TL;DR

This paper demonstrates the first sub-MHz quadrature vacuum squeezing in atomic systems using polarization self-rotation in rubidium vapor, with potential applications in quantum information protocols involving atomic transitions.

Contribution

It introduces a novel method for generating low-frequency vacuum squeezing in atomic vapors, aligning with EIT bandwidths for quantum information use.

Findings

Achieved ~1 dB noise suppression below shot noise from 30 kHz to MHz

First demonstration of sub-MHz quadrature vacuum squeezing in atomic systems

Spectral range matches typical EIT resonance bandwidths

Abstract

We observed squeezed vacuum light at 795 nm in 87Rb vapor via resonant polarization self-rotation, and report noise sidebands suppression of ~1 dB below shot noise level spanning from acoustic (30 kHz) to MHz frequencies. This is the first demonstration of sub-MHz quadrature vacuum squeezing in atomic systems. The spectral range of observed squeezing matches well typical bandwidths of electromagnetically induced transparency (EIT) resonances, making this simple technique for generation of optical fields with non-classical statistics at atomic transitions wavelengths attractive for EIT-based quantum information protocols applications.