Limitations on the quantum non-Gaussian characteristic of Schr\"{o}dinger kitten state generation

TL;DR

This paper analyzes how experimental imperfections affect the quantum non-Gaussian characteristics of Schrödinger kitten states, revealing limitations due to detector properties and highlighting challenges at telecommunication wavelengths.

Contribution

It provides a detailed quantitative assessment of the impact of detector imperfections on Schrödinger kitten state generation, especially at telecommunication wavelengths.

Findings

High dark count rates reduce Wigner function negativity at 1550 nm.

Photon-number-resolving detectors offer no advantage over non-resolving detectors under realistic imperfections.

Detector inefficiencies and dark counts significantly limit non-Gaussian state generation.

Abstract

A quantitative analysis is conducted on the impacts of experimental imperfections in the input state, the detector properties, and their interactions on photon-subtracted squeezed vacuum states in terms of a quantum non-Gaussian character witness and Wigner function. Limitations of the non-classicality and quantum non-Gaussian characteristic of Schr\"{o}dinger kitten states are identified and addressed. The detrimental effects of a photon-number detector on the generation of odd Schr\"{o}dinger kitten state at near-infrared wavelengths ($\sim$ 860 nm) and telecommunication wavelengths ($\sim$ 1550 nm) are presented and analysed. This analysis demonstrates that the high dark count probability of telecommunication-wavelength photon-number detectors significantly undermines the negativity of the Wigner function in Schr\"{o}dinger kitten state generation experiments. For a one-photon-subtracted squeezed vacuum state at $\sim$ 1550 nm, an APD-based photon-number-resolving detector provides no significant advantage over a non-photon-number-resolving detector when imperfections, such as dark count probability and inefficiency, are taken into account.