Quantum state engineering via coherent-state superpositions in traveling optical fields

TL;DR

This paper introduces simple optical schemes using linear elements and homodyne detection to generate high-fidelity nonclassical quantum states, including squeezed and photon number states, with promising success probabilities.

Contribution

The authors propose novel, experimentally feasible schemes for producing diverse nonclassical states via coherent-state superpositions in traveling optical fields.

Findings

High-fidelity state generation demonstrated numerically.

Schemes can produce complex photon number superpositions.

Success probabilities are promising for practical use.

Abstract

We propose two experimental schemes for producing coherent-state superpositions which approximate different nonclassical states conditionally in traveling optical fields. Although these setups are constructed of a small number of linear optical elements and homodyne measurements, they can be used to generate various photon number superpositions in which the number of constituent states can be higher than the number of measurements in the schemes. We determine numerically the parameters to achieve maximal fidelity of the preparation for a large variety of nonclassical states, such as amplitude squeezed states, squeezed number states, binomial states and various photon number superpositions. The proposed setups can generate these states with high fidelities and with success probabilities that can be promising for practical applications.