Nonclassical properties of states engineered by superpositions of quantum operations on classical states

TL;DR

This paper proposes a scheme to manipulate classical quantum states using superpositions of creation and annihilation operators, resulting in the generation of strongly nonclassical states with negative Wigner functions, sub-Poissonian statistics, and squeezing.

Contribution

It introduces a feasible method to engineer nonclassical quantum states from classical states through superpositions of field operators, expanding quantum state control capabilities.

Findings

Superpositions induce negativity in Wigner distribution of coherent states.

Operation changes Gaussian thermal states into non-Gaussian states.

Enhanced nonclassical features like squeezing and sub-Poissonian statistics are observed.

Abstract

We consider an experimentally realizable scheme for manipulating quantum states using a general superposition of products of field annihilation ($\hat{a}$) and creation ($\hat{a}^\dag$) operators of the type ($s \hat{a}\hat{a}^\dag+ t \hat{a}^\dag \hat{a}$), with $s^2 + t^2 = 1$. Such an operation, when applied on states with classical features, is shown to introduce strong nonclassicality. We quantify the generated degree of nonclassicality by the negative volume of Wigner distribution in the phase space and investigate two other observable nonclassical features, sub-Poissonian statistics and squeezing. We find that the operation introduces negativity in the Wigner distribution of an input coherent state and changes the Gaussianity of an input thermal state. This provides the possibility of engineering quantum states with specific nonclassical features.