Drummond, Neil and Lopez Rios, P. and Needs, R. J. and Pickard, C. J. (2011) Quantum Monte Carlo study of a positron in an electron gas. Physical review letters, 107 (20): 207402. ISSN 1079-7114
Abstract
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.