A Multireference Quantum Krylov Algorithm for Strongly Correlated Electrons.
A Multireference Quantum Krylov Algorithm for Strongly Correlated Electrons.
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DOI：
10.1021/acs.jctc.9b01125
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发表时间：
2019-11
影响因子：
5.5
通讯作者：
Nicholas H Stair;Ren-dong Huang;Francesco A. Evangelista
中科院分区：
文献类型：
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作者：
Nicholas H Stair;Ren-dong Huang;Francesco A. Evangelista
介绍了一种适用于多体问题量子模拟的多参考选择量子Krylov(MRSQK)算法。方法abbr是量子相位估计算法的一种低成本替代算法，该算法将目标态生成为非正交Krylov基态的线性组合。该基函数由一组参考状态通过实时进化构造而成，避免了参数的数值优化。讨论了计算重叠矩阵和哈密顿矩阵的非对角矩阵元的一种有效算法，并介绍了一种确定改善线性相关性问题的正交基的选择过程。在线性H6、H8和BeH2上的初步基准表明，MRSQK可以使用非常紧凑的Krylov基准确地预测这些系统的能量。
We introduce a multireference selected quantum Krylov (MRSQK) algorithm suitable for quantum simulation of many-body problems. \methodabbr is a low-cost alternative to the quantum phase estimation algorithm that generates a target state as a linear combination of non-orthogonal Krylov basis states. This basis is constructed from a set of reference states via real-time evolution avoiding the numerical optimization of parameters. An efficient algorithm for the evaluation of the off-diagonal matrix elements of the overlap and Hamiltonian matrices is discussed and a selection procedure is introduced to identify a basis of orthogonal references that ameliorates the linear dependency problem. Preliminary benchmarks on linear H6, H8, and BeH2 indicate that MRSQK can predict the energy of these systems accurately using very compact Krylov bases.