Quantum mode filtering of non-Gaussian states for teleportation-based quantum information processing

TL;DR

This paper introduces a mode-filtering technique for non-Gaussian states generated by photon-subtraction, enhancing their non-classicality and robustness for quantum teleportation in quantum information processing.

Contribution

The authors demonstrate a practical mode-filtering method that improves the non-classical features of non-Gaussian states used in quantum teleportation, facilitating universal quantum information processing.

Findings

Mode-filtered states show stronger negativity of the Wigner function.

Filtered states maintain non-classicality after teleportation.

Technique is applicable to various photon-subtraction protocols.

Abstract

We propose and demonstrate an effective mode-filtering technique of non-Gaussian states generated by photon-subtraction. More robust non-Gaussian states have been obtained by removing noisy low frequencies from the original mode spectrum. We show that non-Gaussian states preserve their non-classicality after quantum teleportation to a higher degree, when they have been mode-filtered. This is indicated by a stronger negativity $-0.033 \pm 0.005$ of the Wigner function at the origin, compared to $-0.018 \pm 0.007$ for states that have not been mode-filtered. This technique can be straightforwardly applied to various kinds of photon-subtraction protocols, and can be a key ingredient in a variety of applications of non-Gaussian states, especially teleportation-based protocols towards universal quantum information processing.