Experimentally demonstrating indefinite causal order algorithms to solve the generalized Deutsch's problem
Abstract
Deutsch's algorithm is the first quantum algorithm to show the advantage over the classical algorithm. Here we generalize Deutsch's problem to functions and propose a new quantum algorithm with indefinite causal order to solve this problem. The new algorithm not only reduces the number of queries to the black-box by half over the classical algorithm, but also significantly reduces the number of required quantum gates over the Deutsch's algorithm. We experimentally demonstrate the algorithm in a stable Sagnac loop interferometer with common path, which overcomes the obstacles of both phase instability and low fidelity of Mach-Zehnder interferometer. The experimental results have shown both an ultra-high and robust success probability . Our work opens up a new path towards solving the practical problems with indefinite casual order quantum circuits.
Cite
@article{arxiv.2305.05416,
title = {Experimentally demonstrating indefinite causal order algorithms to solve the generalized Deutsch's problem},
author = {Wen-Qiang Liu and Zhe Meng and Bo-Wen Song and Jian Li and Qing-Yuan Wu and Xiao-Xiao Chen and Jin-Yang Hong and An-Ning Zhang and Zhang-qi Yin},
journal= {arXiv preprint arXiv:2305.05416},
year = {2023}
}