Number state filtered coherent state

TL;DR

Number state filtered coherent states exhibit nonclassical properties like sub-Poissonian statistics and enhanced phase estimation, and are more resilient to dissipation, with potential applications in quantum key distribution.

Contribution

This paper introduces a scheme for generating number state filtered coherent states and analyzes their nonclassical properties and advantages over photon-added states.

Findings

Filtered states show sub-Poissonian photon statistics

They are more resilient against dissipation than photon-added states

Vacuum filtered states outperform photon-added states in quantum key distribution

Abstract

Number state filtering in coherent states leads to sub-Poissonian photon statistics. These states are more suitable for phase estimation when compared with the coherent states. Nonclassicality of these states is quantified in terms of the negativity of the Wigner function and the entanglement potential. Filtering of the vacuum from a coherent state is almost like the photon-addition. However, filtering makes the state more resilient against dissipation than photon-addition. Vacuum state filtered coherent states perform better than the photon-added coherent states for a two-way quantum key distribution protocol. A scheme to generate these states in multi-photon atom-field interaction is presented.