Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 12840 Prague 2, Czech Republic.
J Chem Phys. 2010 Nov 21;133(19):194106. doi: 10.1063/1.3503767.
Quantum computers are appealing for their ability to solve some tasks much faster than their classical counterparts. It was shown in [Aspuru-Guzik et al., Science 309, 1704 (2005)] that they, if available, would be able to perform the full configuration interaction (FCI) energy calculations with a polynomial scaling. This is in contrast to conventional computers where FCI scales exponentially. We have developed a code for simulation of quantum computers and implemented our version of the quantum FCI algorithm. We provide a detailed description of this algorithm and the results of the assessment of its performance on the four lowest lying electronic states of CH(2) molecule. This molecule was chosen as a benchmark, since its two lowest lying (1)A(1) states exhibit a multireference character at the equilibrium geometry. It has been shown that with a suitably chosen initial state of the quantum register, one is able to achieve the probability amplification regime of the iterative phase estimation algorithm even in this case.
量子计算机因其能够比传统计算机更快地解决某些任务而备受关注。[Aspuru-Guzik 等人，《科学》309, 1704 (2005)]表明，如果有量子计算机，它们将能够以多项式的规模进行全组态相互作用（FCI）能量计算。这与传统计算机形成对比，在传统计算机中，FCI 呈指数级增长。我们已经开发了一种用于模拟量子计算机的代码，并实现了我们版本的量子 FCI 算法。我们提供了该算法的详细描述以及在 CH(2)分子的四个最低电子态上评估其性能的结果。选择这种分子作为基准，是因为其两个最低的（1）A(1)态在平衡几何形状下表现出多参考特征。已经表明，通过选择合适的量子寄存器的初始状态，即使在这种情况下，也能够实现迭代相位估计算法的概率放大模式。
