多光子W态的高效制备

量子纠缠的制备是量子信息科学研究的一个重要课题.利用已有的控制路径门和融合门,给出一类重要的多光子最大纠缠态——W态的制备方案.区别于此前线性光学方案,该方案的实现是确定性的,并且不是基于后验选择的方式,因此可以避免线性光学方案的概率问题以及制备出来的量子态在使用上的局限性.同时方案实现所需的资源仅随光子数的增加而呈线性增长,比之传统线路量子计算模式下的多项式增长有着极大的优化.总之方案的确定性、适用性、高效性等特点,将使得方案更具可行性,也更适用于大规模量子信息过程.

Efficient generation of multi-photon W state

How to create entanglement is an important problem in quantum information processing.In this paper,we propose an experimental scheme to generate multi-photon W state using c-path gate and merging gate introduced in the former works.Compared with the other linear optical schemes,our scheme is deterministic without post-selection,and then there is no probabilistic problem and no limitation on the use of W state.Moreover,the required resources for generation grow linearly with the number of involved photons,which is obviously better than the polynomial growth with the traditional circuit-based quantum computation.This scheme is deterministic,suitability,and efficient,so it is feasible and suitable for large-scale quantum information processing.