We report an experiment to demonstrate a quantum permutation determining algorithm with linear optical system. By employing photon polarization and spatial modes, we realize the quantum ququart states and all the essential permutation transformations. Compared with the classical case, this work determines the parity of the permutation in only one step of evaluation and displays the remarkable speedup of quantum algorithm. This experiment is accomplished in single photon level and exhibits strong universality in quantum computation.
@article{arxiv.1501.06798,
title = {Demonstration of quantum permutation algorithm with a single photon ququart},
author = {Feiran Wang and Yunlong Wang and Ruifeng Liu and Dongxu Chen and Pei Zhang and Hong Gao and Fuli Li},
journal= {arXiv preprint arXiv:1501.06798},
year = {2015}
}