Higher-order nonclassical properties of a shifted symmetric cat state and a one-dimensional continuous superposition of coherent states

TL;DR

This paper explores higher-order nonclassical properties of shifted symmetric cat states and continuous superpositions of coherent states, revealing their nonclassical features and effects of non-Gaussian operations through theoretical analysis.

Contribution

It introduces a detailed analysis of higher-order nonclassical properties in both discrete and continuous superpositions of coherent states, including effects of non-Gaussian operations.

Findings

Higher-order antibunching observed in shifted symmetric cat states

Higher-order sub-Poissonian photon statistics identified in continuous superpositions

Non-Gaussian operations enhance nonclassical features

Abstract

Role of quantum interference in the origin of higher-order nonclassical characteristics of radiation field has been probed vis-a-vis a discrete and a continuous superposition of coherent states. Specifically, the possibilities of observing higher-order nonclassical properties (e.g., higher-order antibunching (HOA), higher-order sub-Poissonian photon statistics (HOSPS), higher-order squeezing (HOS) of Hong-Mandel type and Hillery type) have been investigated using a shifted symmetric cat state that reduces to Yurke-Stoler, even and odd coherent states at various limits. This shifted symmetric cat state which can be viewed as a discrete superposition of coherent states is found to show HOA and HOSPS. Similarly, higher-order nonclassical properties of a one-dimensional continuous superposition of coherent states is also studied here. The investigation has revealed the existence of HOS and HOSPS in the one-dimensional continuous superposition of coherent states studied here. Effect of non-Gaussianity inducing operations (e.g., photon addition and addition followed by subtraction) on these superposition states have also been investigated. Finally, some comparisons have been made between the higher-order nonclassical properties of discrete and continuous superposition of coherent states.