A bridge between the single-photon and squeezed-vacuum state

TL;DR

This paper presents a method to generate and control quantum states that interpolate between single-photon and squeezed-vacuum states using entangled photon pairs and beam splitter interference, enabling versatile quantum state engineering.

Contribution

It introduces a technique to produce tunable quantum states bridging single-photon and squeezed states via heralded detection and adjustable beam splitter ratios.

Findings

Demonstrated control over quantum state properties by varying beam splitter ratio.

Achieved heralded preparation of states between single-photon and squeezed-vacuum.

Validated the method through homodyne tomography measurements.

Abstract

The two modes of the Einstein-Podolsky-Rosen quadrature entangled state generated by parametric down-conversion interfere on a beam splitter of variable splitting ratio. Detection of a photon in one of the beam splitter output channels heralds preparation of a signal state in the other, which is characterized using homodyne tomography. By controlling the beam splitting ratio, the signal state can be chosen anywhere between the single-photon and squeezed state.