An iterative version of the qubit coupled cluster (QCC) method [I. G. Ryabinkin et al., J. Chem. Theory Comput. 2019, 14, 6317] is proposed. The new method seeks to find ground electronic energies of molecules on noisy intermediate-scale quantum devices. Each iteration involves a canonical transformation of the Hamiltonian and employs constant-size quantum circuits at the expense of increasing the Hamiltonian size. We numerically studied the convergence of the method on ground-state calculations for LiH, H2O, and N2 molecules and found that the exact ground-state energies can be systematically approached only if the generators of the QCC ansatz are sampled from a specific set of operators. We report an algorithm for constructing this set that scales linearly with the size of the Hamiltonian.

中文翻译：

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具有有效筛选生成器的迭代Qubit耦合聚类方法。

量子位耦合簇（QCC）方法的迭代版本[IG Ryabinkin等，化学学报，2010年，理论计算。提议[2019，14，6317]。新方法试图在嘈杂的中型量子装置上找到分子的地面电子能量。每次迭代都涉及哈密顿量的规范变换，并采用恒定大小的量子电路，但以增加哈密顿量为代价。我们对LiH，H2O和N2分子的基态计算方法进行了数值研究，发现只有从一组特定的算子中采样QCC ansatz的生成器，才能系统地获得确切的基态能量。我们报告了一种构建此集合的算法，该算法随哈密顿量的大小线性缩放。