Quantum memory for squeezed light

TL;DR

This paper demonstrates the storage and retrieval of squeezed vacuum light in rubidium vapor using electromagnetically induced transparency, analyzing the preservation of quantum squeezing during the process.

Contribution

It presents the first experimental demonstration of storing squeezed light in atomic vapor with detailed analysis of squeezing degradation and phase evolution.

Findings

Stored 1.86-dB squeezed vacuum for 1 microsecond

Recovered pulse shows up to 0.21 dB of squeezing

Identified factors affecting squeezing preservation

Abstract

We produce a 600-ns pulse of 1.86-dB squeezed vacuum at 795 nm in an optical parametric amplifier and store it in a rubidium vapor cell for 1 us using electromagnetically induced transparency. The recovered pulse, analyzed using time-domain homodyne tomography, exhibits up to 0.21+-0.04 dB of squeezing. We identify the factors leading to the degradation of squeezing and investigate the phase evolution of the atomic coherence during the storage interval.