Tencent America, Palo Alto, California 94306, United States.
Centre for Quantum Technologies, National University of Singapore, 117543, Singapore.
J Chem Theory Comput. 2022 Mar 8;18(3):1347-1358. doi: 10.1021/acs.jctc.1c01296. Epub 2022 Feb 22.
Quantum computers have the potential to simulate chemical systems beyond the capability of classical computers. Recent developments in hybrid quantum-classical approaches enable the determinations of the ground or low energy states of molecular systems. Here, we extend near-term quantum simulations of chemistry to time-dependent processes by simulating energy transfer in organic semiconducting molecules. We developed a multiscale modeling workflow that combines conventional molecular dynamics and quantum chemistry simulations with hybrid variational quantum algorithm to compute the exciton dynamics in both the single excitation subspace (i.e., Frenkel Hamiltonian) and the full-Hilbert space (i.e., multiexciton) regimes. Our numerical examples demonstrate the feasibility of our approach, and simulations on IBM Q devices capture the qualitative behaviors of exciton dynamics, but with considerable errors. We present an error mitigation technique that combines experimental results from the variational and Trotter algorithms, and obtain significantly improved quantum dynamics. Our approach opens up new opportunities for modeling quantum dynamics in chemical, biological, and material systems with quantum computers.
量子计算机有潜力模拟超出经典计算机能力的化学系统。混合量子-经典方法的最新进展使得可以确定分子系统的基态或低能态。在这里，我们通过模拟有机半导体分子中的能量转移，将化学的近实时量子模拟扩展到时间相关过程。我们开发了一种多尺度建模工作流程，该流程将传统的分子动力学和量子化学模拟与混合变分量子算法相结合，以在单激发子空间（即 Frenkel 哈密顿量）和全 Hilbert 空间（即多激子）范围内计算激子动力学。我们的数值示例证明了我们方法的可行性，并且在 IBM Q 设备上的模拟可以捕捉激子动力学的定性行为，但存在相当大的误差。我们提出了一种误差缓解技术，该技术结合了变分算法和 Trotter 算法的实验结果，并获得了显著改进的量子动力学。我们的方法为使用量子计算机对化学、生物和材料系统中的量子动力学进行建模开辟了新的机会。
