Zhao Shoukuan, Tang Diandong, Xiao Xiaoxiao, Wang Ruixia, Sun Qiming, Chen Zhen, Cai Xiaoxia, Li Zhendong, Yu Haifeng, Fang Wei-Hai
Beijing Academy of Quantum Information Sciences, Beijing 100193, China.
Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education College of Chemistry, Beijing Normal University, Beijing 100875, China.
J Phys Chem Lett. 2024 Jul 18;15(28):7244-7253. doi: 10.1021/acs.jpclett.4c01314. Epub 2024 Jul 8.
Conical intersections (CIs) are pivotal in many photochemical processes. Traditional quantum chemistry methods, such as the state-average multiconfigurational methods, face computational hurdles in solving the electronic Schrödinger equation within the active space on classical computers. While quantum computing offers a potential solution, its feasibility in studying CIs, particularly on real quantum hardware, remains largely unexplored. Here, we present the first successful realization of a hybrid quantum-classical state-average complete active space self-consistent field method based on the variational quantum eigensolver (VQE-SA-CASSCF) on a superconducting quantum processor. This approach is applied to investigate CIs in two prototypical systems─ethylene (CH) and triatomic hydrogen (H). We illustrate that VQE-SA-CASSCF, coupled with ongoing hardware and algorithmic enhancements, can lead to a correct description of CIs on existing quantum devices. These results lay the groundwork for exploring the potential of quantum computing to study CIs in more complex systems in the future.
锥形交叉点（CIs）在许多光化学过程中起着关键作用。传统量子化学方法，如状态平均多组态方法，在经典计算机上求解活性空间内的电子薛定谔方程时面临计算障碍。虽然量子计算提供了一种潜在的解决方案，但其在研究锥形交叉点方面的可行性，特别是在实际量子硬件上的可行性，在很大程度上仍未得到探索。在此，我们展示了基于变分量子本征求解器（VQE-SA-CASSCF）在超导量子处理器上首次成功实现的混合量子-经典状态平均完全活性空间自洽场方法。该方法被应用于研究两个典型体系——乙烯（CH）和三原子氢（H）中的锥形交叉点。我们表明，VQE-SA-CASSCF与持续的硬件和算法改进相结合，可以在现有量子设备上对锥形交叉点进行正确描述。这些结果为未来探索量子计算在研究更复杂体系中锥形交叉点的潜力奠定了基础。
