Quantum Algorithm for the Direct Calculations of Vertical Ionization Energies
Quantum Algorithm for the Direct Calculations of Vertical Ionization Energies
复制标题
直接计算垂直电离能的量子算法
DOI：
10.1021/acs.jpclett.1c00283
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Takui Takeji
中科院分区：
文献类型：
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作者：
Sugisaki Kenji;Toyota Kazuo;Sato Kazunobu;Shiomi Daisuke;Takui Takeji
最近，提出了一种量子算法，其能够直接计算具有不同自旋量子数的两个电子状态之间的能隙，而不检查各个电子状态的总能量。这种量子算法保证了指数加速比，就像基于量子相位估计（QPE）的全CI一样，成本要低得多。在这项工作中，我们提出了一个修改的量子电路的自旋态能隙的直接计算，以减少量子比特和量子门的数量，扩展的量子算法的垂直电离能的直接计算。对轻原子（He、Li、Be、B、C和N）和小分子（HF、BF、CF、CO、O2、NO、CN、F2、H2O和NH3）电离的量子电路数值模拟表明，所提出的量子算法提供的垂直电离能精度在0.1 eV以内。
Recently, a quantum algorithm that is capable of directly calculating the energy gap between two electronic states having different spin quantum numbers without inspecting the total energy of the individual electronic states was proposed. This quantum algorithm guarantees an exponential speedup, like quantum phase estimation (QPE)-based full-CI, with much lower costs. In this work, we propose a modified quantum circuit for the direct calculations of spin state energy gaps to reduce the number of qubits and quantum gates, extending the quantum algorithm to the direct calculation of vertical ionization energies. Numerical quantum circuit simulations for the ionization of light atoms (He, Li, Be, B, C, and N) and small molecules (HF, BF, CF, CO, O2, NO, CN, F2, H2O, and NH3) revealed that the proposed quantum algorithm affords the vertical ionization energies within 0.1 eV of precision.