Experimental study of decoherence of the two-mode squeezed vacuum state via second harmonic generation

TL;DR

This paper presents an experimental scheme to study decoherence in a two-mode squeezed vacuum state by analyzing its second harmonic generation signal, providing new insights into quantum correlations' decay.

Contribution

It introduces a novel experimental method to directly measure decoherence of phase-sensitive quantum correlations in a two-mode squeezed vacuum state.

Findings

Successfully extracted decoherence of quantum correlations

Demonstrated the decay of entanglement over time

Provided experimental insights into decoherence of squeezed states

Abstract

Decoherence remains one of the most serious challenges to the implementation of quantum technology. It appears as a result of the transformation over time of a quantum superposition state into a classical mixture due to the quantum system interacting with the environment. Since quantum systems are never completely isolated from their environment, decoherence therefore cannot be avoided in realistic situations. Decoherence has been extensively studied, mostly theoretically, because it has many important implications in quantum technology, such as in the fields of quantum information processing, quantum communication and quantum computation. Here we report a novel experimental scheme on the study of decoherence of a two-mode squeezed vacuum state via its second harmonic generation signal. Our scheme can directly extract the decoherence of the phase-sensitive quantum correlation $\langle \hat{a}\hat{b}\rangle$ between two entangled modes $a$ and $b$. Such a correlation is the most important characteristic of a two-mode squeezed state. More importantly, this is an experimental study on the decoherence effect of a squeezed vacuum state, which has been rarely investigated.