Resource reduction for simultaneous generation of two types of continuous variable nonclassical states

TL;DR

This paper demonstrates an experimental setup that simultaneously generates and detects two types of continuous variable nonclassical states, including squeezed and entangled states, using a single optical parametric amplifier and two filter cavities, with significant noise reduction.

Contribution

It introduces a resource-efficient method for generating multiple nonclassical states simultaneously with active stabilization, improving quantum state generation techniques.

Findings

Noise variance of squeezed states is 10.2 dB below shot noise limit.

Correlation variances of entangled states are 10.0 dB below shot noise limit.

Successful active stabilization of all system freedoms.

Abstract

We demonstrate experimentally the simultaneous generation and detection of two types of continuous variable nonclassical states from one type-0 phase-matching optical parametric amplification (OPA) and subsequent two ring filter cavities (RFCs). The output field of the OPA includes the baseband {\omega}0 and sideband modes {\omega}0+/-n{\omega}f subjects to the cavity resonance condition, which are separated by two cascaded RFCs. The first RFC resonates with half the pump wavelength {\omega}0 and the transmitted baseband component is a squeezed state. The reflected fields of the first RFC, including the sideband modes {\omega}0+/-{\omega}f, are separated by the second RFC, construct Einstein-Podolsky-Rosen entangled state. All freedoms, including the filter cavities for sideband separation and relative phases for the measurements of these sidebands, are actively stabilized. The noise variance of squeezed states is 10.2 dB below the shot noise limit (SNL), the correlation variances of both quadrature amplitude-sum and quadrature phase-difference for the entanglement state are 10.0 dB below the corresponding SNL.