Correlations in two-dimensional electron gas: Random-phase approximation with exchange and ladder results

¹ Center for Theory and Simulation in Science and Engeneering and Laboratory of Atomic and Solid State Physics Cornell University, Ithaca, New York 14853 (USA)
² Departament d'Estructura i Constituents de la Matéria, Facultat de Fisica Universitat de Barcelona, E-08028 Barcelona, Spain
³ Sophia University, Department of Physics, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102, Japan

Received: 29 January 1997
Accepted: 23 October 1997

Abstract

We have evaluated the density-density response of the two-dimensional electron gas at zero temperature by solving the Dyson equation for the particle-hole Green's function, including exchange Coulomb matrix elements and short-range contributions in the ladder approximation. We study the effect of these correlations on the total energy, compressibility per particle, local field factor G(q), static structure factor and pair-correlation function. Results are compared with the normal random-phase approximation, local field theories and quantum Monte Carlo calculations.