A Full Quantum Eigensolver for Quantum Chemistry Simulations  

作　　者：Shijie Wei Hang Li GuiLu Long 

机构地区：[1]Beijing Academy of Quantum Information Sciences,Beijing 100193,China [2]State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics,Tsinghua University,Beijing 100084,China [3]Beijing National Research Center for Information Science and Technology and School of Information Tsinghua University,Beijing 100084,China [4]Frontier Science Center for Quantum Information,Beijing 100084,China

出　　处：《Research》2020年第1期111-121,共11页研究（英文）

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).

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.

关 键 词：CONVERGENCE QUANTUM ITERATION 

分 类 号：O41[理学—理论物理]