Quantum Fredkin and Toffoli gates on a versatile programmable silicon photonic chip
Yuan Li, Lingxiao Wan, Hui Zhang, Huihui Zhu, Yuzhi Shi, L. K. Chin, Xiaoqi Zhou, L. C. Kwek, A. Q. Liu
Abstract
Abstract Quantum logic gates are backbones of quantum information processing (QIP), wherein the typical three-qubit Fredkin and Toffoli gates are essential in quantum computation and communication. So far, the quantum Fredkin gate has only been demonstrated with pre-entangled input states in free-space optics, which limits its usage for independent input photons. Here, we put forward an exquisite scheme and experimentally perform a proof-of-principle demonstration of three-qubit Fredkin and Toffoli gates on a programmable quantum photonic chip. Our scheme can also be used to realize a series of other two-qubit quantum gates. Our work sheds light on the merits of quantum photonic chip in implementing quantum logic gates, and paves the way for advanced quantum chip processors.