Quantum memory of a squeezed vacuum for arbitrary frequency sidebands

TL;DR

This paper presents a quantum memory technique capable of storing and retrieving arbitrary frequency sidebands of a squeezed vacuum, demonstrating high-quality preservation of squeezing in a cold atom system.

Contribution

It introduces a compatible quantum memory method for continuous-variable light, enabling storage of arbitrary frequency sidebands with high fidelity.

Findings

Stored 2MHz sidebands of squeezed vacuum for 3 microseconds

Retrieved squeezing of -0.44 dB, the highest reported for such a pulse

Demonstrated compatibility with current quantum information processing

Abstract

We have developed a quantum memory technique that is completely compatible with current quantum information processing for continuous variables of light, where arbitrary frequency sidebands of a squeezed vacuum can be stored and retrieved using bichromatic electromagnetic induced transparency. 2MHz sidebands of squeezed vacuum pulses with temporal widths of 470ns and a squeezing level of -1.78 +- 0.02dB were stored for 3us in the laser-cooled 87Rb atoms. -0.44 +- 0.02dB of squeezing was retrieved, which is the highest squeezing ever reported for a retrieved pulse.