_version_ 1866916288991854592
author Guo, Shaojun
Sun, Jinzhao
Qian, Haoran
Gong, Ming
Zhang, Yukun
Chen, Fusheng
Ye, Yangsen
Wu, Yulin
Cao, Sirui
Liu, Kun
Zha, Chen
Ying, Chong
Zhu, Qingling
Huang, He-Liang
Zhao, Youwei
Li, Shaowei
Wang, Shiyu
Yu, Jiale
Fan, Daojin
Wu, Dachao
Su, Hong
Deng, Hui
Rong, Hao
Li, Yuan
Zhang, Kaili
Chung, Tung-Hsun
Liang, Futian
Lin, Jin
Xu, Yu
Sun, Lihua
Guo, Cheng
Li, Na
Huo, Yong-Heng
Peng, Cheng-Zhi
Lu, Chao-Yang
Yuan, Xiao
Zhu, Xiaobo
Pan, Jian-Wei
author_facet Guo, Shaojun
Sun, Jinzhao
Qian, Haoran
Gong, Ming
Zhang, Yukun
Chen, Fusheng
Ye, Yangsen
Wu, Yulin
Cao, Sirui
Liu, Kun
Zha, Chen
Ying, Chong
Zhu, Qingling
Huang, He-Liang
Zhao, Youwei
Li, Shaowei
Wang, Shiyu
Yu, Jiale
Fan, Daojin
Wu, Dachao
Su, Hong
Deng, Hui
Rong, Hao
Li, Yuan
Zhang, Kaili
Chung, Tung-Hsun
Liang, Futian
Lin, Jin
Xu, Yu
Sun, Lihua
Guo, Cheng
Li, Na
Huo, Yong-Heng
Peng, Cheng-Zhi
Lu, Chao-Yang
Yuan, Xiao
Zhu, Xiaobo
Pan, Jian-Wei
contents Quantum computational chemistry has emerged as an important application of quantum computing. Hybrid quantum-classical computing methods, such as variational quantum eigensolvers (VQE), have been designed as promising solutions to quantum chemistry problems, yet challenges due to theoretical complexity and experimental imperfections hinder progress in achieving reliable and accurate results. Experimental works for solving electronic structures are consequently still restricted to nonscalable (hardware efficient) or classically simulable (Hartree-Fock) ansatz, or limited to a few qubits with large errors. The experimental realisation of scalable and high-precision quantum chemistry simulation remains elusive. Here, we address the critical challenges {associated with} solving molecular electronic structures using noisy quantum processors. Our protocol presents significant improvements in the circuit depth and running time, key metrics for chemistry simulation. Through systematic hardware enhancements and the integration of error mitigation techniques, we push forward the limit of experimental quantum computational chemistry and successfully scale up the implementation of VQE with an optimised unitary coupled-cluster ansatz to 12 qubits. We produce high-precision results of the ground-state energy for molecules with error suppression by around two orders of magnitude. We achieve chemical accuracy for H$_2$ at all bond distances and LiH at small bond distances in the experiment, even beyond the two recent concurrent works. Our work demonstrates a feasible path towards a scalable solution to electronic structure calculation, validating the key technological features and identifying future challenges for this goal.
format Preprint
id arxiv_https___arxiv_org_abs_2212_08006
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Experimental quantum computational chemistry with optimised unitary coupled cluster ansatz
Guo, Shaojun
Sun, Jinzhao
Qian, Haoran
Gong, Ming
Zhang, Yukun
Chen, Fusheng
Ye, Yangsen
Wu, Yulin
Cao, Sirui
Liu, Kun
Zha, Chen
Ying, Chong
Zhu, Qingling
Huang, He-Liang
Zhao, Youwei
Li, Shaowei
Wang, Shiyu
Yu, Jiale
Fan, Daojin
Wu, Dachao
Su, Hong
Deng, Hui
Rong, Hao
Li, Yuan
Zhang, Kaili
Chung, Tung-Hsun
Liang, Futian
Lin, Jin
Xu, Yu
Sun, Lihua
Guo, Cheng
Li, Na
Huo, Yong-Heng
Peng, Cheng-Zhi
Lu, Chao-Yang
Yuan, Xiao
Zhu, Xiaobo
Pan, Jian-Wei
Quantum Physics
Quantum computational chemistry has emerged as an important application of quantum computing. Hybrid quantum-classical computing methods, such as variational quantum eigensolvers (VQE), have been designed as promising solutions to quantum chemistry problems, yet challenges due to theoretical complexity and experimental imperfections hinder progress in achieving reliable and accurate results. Experimental works for solving electronic structures are consequently still restricted to nonscalable (hardware efficient) or classically simulable (Hartree-Fock) ansatz, or limited to a few qubits with large errors. The experimental realisation of scalable and high-precision quantum chemistry simulation remains elusive. Here, we address the critical challenges {associated with} solving molecular electronic structures using noisy quantum processors. Our protocol presents significant improvements in the circuit depth and running time, key metrics for chemistry simulation. Through systematic hardware enhancements and the integration of error mitigation techniques, we push forward the limit of experimental quantum computational chemistry and successfully scale up the implementation of VQE with an optimised unitary coupled-cluster ansatz to 12 qubits. We produce high-precision results of the ground-state energy for molecules with error suppression by around two orders of magnitude. We achieve chemical accuracy for H$_2$ at all bond distances and LiH at small bond distances in the experiment, even beyond the two recent concurrent works. Our work demonstrates a feasible path towards a scalable solution to electronic structure calculation, validating the key technological features and identifying future challenges for this goal.
title Experimental quantum computational chemistry with optimised unitary coupled cluster ansatz
topic Quantum Physics
url https://arxiv.org/abs/2212.08006