Perturbative Quantum Monte Carlo Method for Nuclear Physics.
Perturbative Quantum Monte Carlo Method for Nuclear Physics.
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DOI：
10.1103/physrevlett.128.242501
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发表时间：
2021-11
影响因子：
8.6
通讯作者：
B. Lu;Ning Li;S. Elhatisari;Yuan-Zhuo Ma;Dean Lee;U. Meissner
中科院分区：
文献类型：
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作者：
B. Lu;Ning Li;S. Elhatisari;Yuan-Zhuo Ma;Dean Lee;U. Meissner
虽然一阶微扰理论通常用于量子蒙特卡罗 (QMC) 计算，但高阶项提出了重大的数值挑战。我们提出了一种在投影 QMC 计算中计算微扰校正的新方法。我们通过计算高达二阶的核基态能量来演示该方法，以实现真实的手性相互作用。我们通过围绕维格纳 SU(4) 极限扩展哈密顿量，计算了高达 ^{16}O 的几个轻核的结合能，并发现与数据良好吻合。与扰动级数的自然排序相反，我们发现了非常大的二阶能量修正。发生这种情况是因为扰动相互作用打破了未扰动哈密顿量的对称性。我们的方法不存在符号问题，可应用于核物理、凝聚态物理、超冷原子和量子化学中多体系统的 QMC 计算。
While first order perturbation theory is routinely used in quantum Monte Carlo (QMC) calculations, higher-order terms present significant numerical challenges. We present a new approach for computing perturbative corrections in projection QMC calculations. We demonstrate the method by computing nuclear ground state energies up to second order for a realistic chiral interaction. We calculate the binding energies of several light nuclei up to ^{16}O by expanding the Hamiltonian around the Wigner SU(4) limit and find good agreement with data. In contrast to the natural ordering of the perturbative series, we find remarkably large second-order energy corrections. This occurs because the perturbing interactions break the symmetries of the unperturbed Hamiltonian. Our method is free from the sign problem and can be applied to QMC calculations for many-body systems in nuclear physics, condensed matter physics, ultracold atoms, and quantum chemistry.