Higher-Order Nonclassicality in Photon Added and Subtracted Qudit States

TL;DR

This paper investigates how photon addition and subtraction influence higher-order nonclassical properties of qudit states, demonstrating increased nonclassicality with more photons added or subtracted, using theoretical analysis and optical tomograms.

Contribution

It introduces a detailed analysis of higher-order nonclassicality in photon added and subtracted qudit states, providing quantitative measures and experimental verification methods.

Findings

Nonclassicality increases with photon addition (r).

Higher-order nonclassical witnesses confirm strong nonclassical behavior.

Optical tomograms enable experimental verification of nonclassical features.

Abstract

Higher-order nonclassical properties of r photon added and t photon subtracted qudit states (referred to as rPAQS and tPSQS, respectively) are investigated here to answer: How addition and subtraction of photon can be used engineer higher-order nonclassical properties of qudit states? To obtain the answer higher-order moment of relevant bosonic field operators are first obtained for rPAQS and tPSQS, and subsequently the same is used to study the higher-order nonclassical properties of the corresponding states. A few witnesses of higher-order nonclassicality (e.g. Higher-Order Antibunching, Higher-Order Squeezing of Hillery type, Higher-Order sub-Poissonian Photon statistics) are first used to establish that rPAQS and tPSQS are highly nonclassical. These witnesses are found to indicate that the amount of nonclassicality enhances with the number of photon added (r). To quantitatively establish this observation and to make a comparison between rPAQS and tPSQS, volumes of the negative part of Wigner function (nonclassical volume) of rPAQS and tPSQS are computed as a quantitative measure of nonclassicality. Finally, for the sake of verifiablity of the obtained results, optical tomograms are also reported which can be obtained experimentally and used to produce Wigner function (which is not directly measurable in general) by the Radon transform. Throughout the study, a particular type of qudit state named as a new generalized binomial state is used as an example.