The development of high-fidelity two-qubit quantum gates is essential for digital quantum computing. Here, we propose and realize an all-microwave parametric Controlled-Z (CZ) gates by coupling strength modulation in a superconducting Transmon qubit system with tunable couplers. After optimizing the design of the tunable coupler together with the control pulse numerically, we experimentally realized a 100 ns CZ gate with high fidelity of 99.38%±0.34% and the control error being 0.1%. We note that our CZ gates are not affected by pulse distortion and do not need pulse correction, {providing a solution for the real-time pulse generation in a dynamic quantum feedback circuit}. With the expectation of utilizing our all-microwave control scheme to reduce the number of control lines through frequency multiplexing in the future, our scheme draws a blueprint for the high-integrable quantum hardware design.
@article{arxiv.2202.06616,
title = {Realization of fast all-microwave CZ gates with a tunable coupler},
author = {Shaowei Li and Daojin Fan and Ming Gong and Yangsen Ye and Xiawei Chen and Yulin Wu and Huijie Guan and Hui Deng and Hao Rong and He-Liang Huang and Chen Zha and Kai Yan and Shaojun Guo and Haoran Qian and Haibin Zhang and Fusheng Chen and Qingling Zhu and Youwei Zhao and Shiyu Wang and Chong Ying and Sirui Cao and Jiale Yu and Futian Liang and Yu Xu and Jin Lin and Cheng Guo and Lihua Sun and Na Li and Lianchen Han and Cheng-Zhi Peng and Xiaobo Zhu and Jian-Wei Pan},
journal= {arXiv preprint arXiv:2202.06616},
year = {2022}
}