Comment on "Single-mode excited entangled coherent states"

TL;DR

This paper critiques a previous claim about the behavior of concurrence in single-mode excited entangled coherent states, arguing that the earlier conclusion about photon excitations reducing entanglement in strong fields is incorrect.

Contribution

It provides a correction to prior work by demonstrating that photon excitations do not necessarily decrease entanglement in the strong field regime.

Findings

The previous claim about concurrence tending to zero is incorrect.

Photon excitations do not always lead to decreased entanglement.

The paper clarifies the behavior of entanglement in excited coherent states.

Abstract

In Xu and Kuang (\textit{J. Phys. A: Math. Gen.} 39 (2006) L191), the authors claim that, for single-mode excited entangled coherent states $| \Psi_{\pm}(\alpha,m)>$, \textquotedblleft the photon excitations lead to the decrease of the concurrence in the strong field regime of $| \alpha | ^{2}$ and the concurrence tends to zero when $| \alpha | ^{2}\to \infty$". This is wrong.