A Full Quantum Eigensolver for Quantum Chemistry Simulations

作     者：Shijie Wei Hang Li GuiLu Long 

作者机构：Beijing Academy of Quantum Information SciencesBeijing 100193China State Key Laboratory of Low-Dimensional Quantum Physics and Department of PhysicsTsinghua UniversityBeijing 100084China Beijing National Research Center for Information Science and Technology and School of Information Tsinghua UniversityBeijing 100084China Frontier Science Center for Quantum InformationBeijing 100084China 

出 版 物：《Research》 (研究（英文）)

年 卷 期：2020年第2020卷第1期

页      面：111-121页

核心收录：

学科分类：07[理学] 070201[理学-理论物理] 0702[理学-物理学] 

基　　金：This research was supported by the National Basic Research Program of China.We gratefully acknowledges support from theNationalNatural Science Foundation of China under Grant No.11974205 and No.11774197 the National Key Research and Development Program of China(2017YFA0303700) the Key Research and Development Program of Guangdong Province(2018B030325002) Beijing Advanced Innovation Center for Future Chip(ICFC). 

主　　题：convergence quantum iteration 

摘      要：Quantum simulation of quantum chemistry is one of the most compelling applications of quantum computing.It is of particular importance in areas ranging from materials science,biochemistry,and condensed matter physics.Here,we propose a full quantum eigensolver(FQE)algorithm to calculate the molecular ground energies and electronic structures using quantum gradient descent.Compared to existing classical-quantum hybrid methods such as variational quantum eigensolver(VQE),our method removes the classical optimizer and performs all the calculations on a quantum computer with faster convergence.The gradient descent iteration depth has a favorable complexity that is logarithmically dependent on the system size and inverse of the precision.Moreover,the FQE can be further simplified by exploiting a perturbation theory for the calculations of intermediate matrix elements and obtaining results with a precision that satisfies the requirement of chemistry application.The full quantum eigensolver can be implemented on a near-term quantum computer.With the rapid development of quantum computing hardware,the FQE provides an efficient and powerful tool to solve quantum chemistry problems.