Quantum engineering of squeezed states for quantum communication and metrology

TL;DR

This paper reports the experimental creation of broadband squeezed light states at very low frequencies, advancing quantum communication, precision measurement, and macroscopic entanglement research.

Contribution

It demonstrates the first observation of low-frequency squeezed states down to 1 Hz, enabling new applications in quantum information and metrology.

Findings

First observation of squeezed states at 1 Hz frequency

Broadband squeezing suitable for gravitational wave detectors

Potential to observe macroscopic entanglement

Abstract

We report the experimental realization of squeezed quantum states of light, tailored for new applications in quantum communication and metrology. Squeezed states in a broad Fourier frequency band down to 1 Hz has been observed for the first time. Nonclassical properties of light in such a low frequency band is required for high efficiency quantum information storage in electromagnetically induced transparency (EIT) media. The states observed also cover the frequency band of ultra-high precision laser interferometers for gravitational wave detection and can be used to reach the regime of quantum non-demolition interferometry. And furthermore, they cover the frequencies of motions of heavily macroscopic objects and might therefore support the attempts to observe entanglement in our macroscopic world.