Quantum Monte Carlo Study of a Positron in an Electron Gas
Quantum Monte Carlo Study of a Positron in an Electron Gas
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DOI：
10.1103/physrevlett.107.207402
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发表时间：
2011-11-08
影响因子：
8.6
通讯作者：
Pickard, C. J.
中科院分区：
文献类型：
--
作者：
Drummond, N. D.;Rios, P. Lopez;Pickard, C. J.
用量子蒙特卡罗方法计算了均匀电子气中正电子的弛豫能、对关联函数和湮灭对动量密度。我们发现更小的弛豫能和接触对相关函数的重要低密度制度比早期的研究预测。由于电子-电子和电子-正电子关联效应的抵消，我们的湮灭对动量密度在费米动量之上几乎为零。
Quantum Monte Carlo calculations of the relaxation energy, pair-correlation function, and annihilating-pair momentum density are presented for a positron immersed in a homogeneous electron gas. We find smaller relaxation energies and contact pair-correlation functions in the important low-density regime than predicted by earlier studies. Our annihilating-pair momentum densities have almost zero weight above the Fermi momentum due to the cancellation of electron-electron and electron-positron correlation effects.