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arXiv 2201.09214quant-ph
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利用有效哈密顿理论减小自适应变分量子算法中的电路深度

Reducing circuit depth in adaptive variational quantum algorithms via effective Hamiltonian theories

Jie Liu, Zhenyu Li, Jinlong Yang

摘要:

电子结构模拟是量子计算机的一个预期应用。由于强关联系统中存在高维的量子纠缠,进行这种模拟所需的量子资源远远超出了当前量子器件的能力。为了降低量子线路的复杂性,有人建议将电子关联的一部分合并到有效哈密顿量中,有效哈密顿量通常从电子哈密顿量的相似变换获得。在这项工作中,我们引入了一个新的变换的形式的产品的线性组合的激发运营商构建有效的哈密顿量与有限项。为了证明它的准确性,我们还考虑了一个等效的自适应变分算法与此变换,并表明它可以获得一个准确的基态波函数。该变换定义的有效哈密顿量被引入到自适应变分量子算法中,以保持恒定尺寸的量子线路。新的计算方案进行了评估,通过对小分子进行数值模拟。化学精度是实现了一个更浅的电路深度。

英文摘要:

Electronic structure simulation is an anticipated application for quantum computers. Due to high-dimensional quantum entanglement in strongly correlated systems, the quantum resources required to perform such simulations are far beyond the capacity of current quantum devices. To reduce the quantum circuit complexity, it has been suggested to incorporate a part of the electronic correlation into an effective Hamiltonian, which is often obtained from a similarity transformation of the electronic Hamiltonian. In this work, we introduce a new transformation in the form of a product of a linear combination of excitation operators to construct the effective Hamiltonian with finite terms. To demonstrate its accuracy, we also consider an equivalent adaptive variational algorithm with this transformation and show that it can obtain an accurate ground state wave function. The effective Hamiltonian defined with this new transformation is incorporated into the adaptive variational quantum algorithms to maintain constant-size quantum circuits. The new computational scheme is assessed by performing numerical simulations for small molecules. Chemical accuracy is achieved with a much shallower circuit depth.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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