Geometric quantum adiabatic methods for quantum chemistry
Geometric quantum adiabatic methods for quantum chemistry
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DOI：
10.1103/physrevresearch.4.033045
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发表时间：
2021-12
影响因子：
4.2
通讯作者：
Hongye Yu;D. Lu;Qin Wu;T. Wei
中科院分区：
文献类型：
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作者：
Hongye Yu;D. Lu;Qin Wu;T. Wei
现有的量子化学量子算法在分子的平衡几何附近工作得很好，但是当化学键在大的原子距离处断裂时，结果可能变得不稳定。对于任何绝热方法，这通常会导致严重的问题，如能级交叉和/或能隙关闭沿着绝热evolution path.在这项工作中，我们提出了一个量子算法的基础上绝热evolution来获得分子的本征态和本征能在量子化学中，利用一个光滑的几何变形通过改变键长和键角。即使是简单的化学键均匀拉伸，该算法也比我们以前的绝热方法[Phys. Rev. Research 3，013104（2021）]执行得更稳定，并实现了更好的准确性。它解决了大原子距离下绝热演化过程中的能隙闭合和能级沿着交叉问题。我们在几个例子中证明了它的实用性，包括H${}_2 $O，CH${}_2$，和H${}_2$+D${}_2\rightarrow $2HD的化学反应。此外，我们的保真度分析表明，即使有限的键长变化，我们的算法仍然实现了高保真的基态。
Existing quantum algorithms for quantum chemistry work well near the equilibrium geometry of molecules, but the results can become unstable when the chemical bonds are broken at large atomic distances. For any adiabatic approach, this usually leads to serious problems, such as level crossing and/or energy gap closing along the adiabatic evolution path. In this work, we propose a quantum algorithm based on adiabatic evolution to obtain molecular eigenstates and eigenenergies in quantum chemistry, which exploits a smooth geometric deformation by changing bond lengths and bond angles. Even with a simple uniform stretching of chemical bonds, this algorithm performs more stably and achieves better accuracy than our previous adiabatic method [Phys. Rev. Research 3, 013104 (2021)]. It solves the problems related to energy gap closing and level crossing along the adiabatic evolution path at large atomic distances. We demonstrate its utility in several examples, including H${}_2$O, CH${}_2$, and a chemical reaction of H${}_2$+D${}_2\rightarrow$ 2HD. Furthermore, our fidelity analysis demonstrates that even with finite bond length changes, our algorithm still achieves high fidelity with the ground state.