We report the preparation and verification of a genuine 12-qubit entanglement in a superconducting processor. The processor that we designed and fabricated has qubits lying on a 1D chain with relaxation times ranging from 29.6 to 54.6 μs. The fidelity of the 12-qubit entanglement was measured to be above 0.5544±0.0025, exceeding the genuine multipartite entanglement threshold by 21 statistical standard deviations. Our entangling circuit to generate linear cluster states is depth-invariant in the number of qubits and uses single- and double-qubit gates instead of collective interactions. Our results are a substantial step towards large-scale random circuit sampling and scalable measurement-based quantum computing.
@article{arxiv.1811.02292,
title = {Genuine 12-qubit entanglement on a superconducting quantum processor},
author = {Ming Gong and Ming-Cheng Chen and Yarui Zheng and Shiyu Wang and Chen Zha and Hui Deng and Zhiguang Yan and Hao Rong and Yulin Wu and Shaowei Li and Fusheng Chen and Youwei Zhao and Futian Liang and Jin Lin and Yu Xu and Cheng Guo and Lihua Sun and Anthony D. Castellano and Haohua Wang and Chengzhi Peng and Chao-Yang Lu and Xiaobo Zhu and Jian-Wei Pan},
journal= {arXiv preprint arXiv:1811.02292},
year = {2019}
}