在量子纠缠中态的演化是一个幺正演化过程,而局域幺正变换不改变体系的纠缠特性。基于Hadamard变换提出一种局域幺正变换方法, 将Yeo和Chua提出的四粒子最大纠缠态及Borras等提出的六粒子纠缠态变换成纠缠特性完全相同的简单形式的四粒子和六粒子纠缠态,为实现制备及应用提供了理论依据。 这些纠缠态具有更简单的表达式和特殊的纠缠特性,在量子隐形传态、量子密集编码、量子安全直接通信等方面有潜在应用前景。

In quantum entanglement, the evolution of states is a unitary evolution process, and local unitary transformation does not change the system entanglement properties. A local unitary transformation method is proposed based on Hadamard transform. The four particle maximum entangled states proposed by Yeo and Chua and six particle entangled states proposed by Borras et al. are transformed into four and six particle entangled states in simple form with exactly the same entanglement properties, which provides a theoretical basis for the relization of preparation and application. These entangled states have simpler expressions and special entanglement properties, and they have a potential application prospects in quantum teleportation, quantum dense coding, quantum secure direct communication and so on.