文摘
This paper describes the fastest quantum algorithm at this moment for the quantum Fourier transform (QFT) over symmetric groups. We provide a new FFT (classical) algorithm over symmetric groups and then transform it to a quantum algorithm. The complexity of our QFT algorithm is O(n3logn), faster than the existing O(n4logn) QFT algorithm. In addition, we show that the algorithm can be performed in O(n3) if the use of threshold gates is allowed.