We proposed two entanglement concentration protocols (ECPs) to obtain maximally entangled Greenberger-Horne-Zeilinger (GHZ)-type entangled coherent state (ECS) from the corresponding partially entangled GHZ-type ECSs. We obtained the first ECP using a partially entangled GHZ-type ECS assisted with a superposition of single-mode coherent state, however the second ECP is designed using two copies of partially entangled GHZ-type ECSs. The success probabilities have also been calculated and discussed for both the ECPs. We have further compared the success probabilities of our first ECP for 3-mode GHZ-type ECS with an ECP of 3-mode W-type ECS and found that our ECP is more efficient (maximal success probabilities) for larger value (β = 0.7) of state parameter. For the physical realization, two optical circuits (for two ECPs) using linear optical elements, viz 50:50 beam splitter, phase shifter, and photon detectors are provided, which support the future experimental implementation possible with the present technology.

我们提出了两种纠缠集中协议（ECP），以从相应的部分纠缠GHZ型ECS获得最大纠缠的Greenberger-Horne-Zeilinger（GHZ）型纠缠相干态（ECS）。我们使用部分纠缠的GHZ型ECS与单模相干态的叠加进行辅助获得了第一个ECP，但是第二个ECP使用了部分纠缠的GHZ型ECS的两个副本进行设计。还计算了两个ECP的成功概率并进行了讨论。我们进一步比较了我们的第一个三模GHZ型ECS的ECP与三模W型ECS的ECP的成功概率，发现对于更大的价值（β，我们的ECP更有效（最大成功概率）。= 0.7）状态参数。为了物理实现，提供了使用线性光学元件的两个光学电路（用于两个ECP），即50:50分束器，移相器和光子检测器，它们支持使用本技术可能进行的未来实验实施。