Comparative study of screened inter-layer interactions in the Coulomb drag effect in bilayer electron systems

Coulomb drag experiments in which the inter-layer resistivity is measured are important as they provide information on the Coulomb interactions in bilayer systems. When the layer densities are low correlation effects become significant to account for the quantitative description of experimental results. We investigate systematically various models of effective inter-layer interactions in a bilayer system and compare our results with recent experiments. In the low density regime, the correlation effects are included via the intra- and inter-layer local-field corrections. We employ several theoretical approaches to construct static local-field corrections. Our comparative study demonstrates the importance of including the correlation effects accurately in the calculation of drag resistivity. Recent experiments performed at low layer densities are adequately described by effective inter-layer interactions incorporating static correlations.Comment: Final Version. To appear in Phys. Rev.

Spin-density functional approach to thermodynamic and structural consistence in the charge and spin response of an electron gas

We use spin-density functional theory to obtain novel expressions for the charge and spin local-field factors of an electron gas in terms of its electron-pair structure factors. These expressions (i) satisfy the compressibility and spin susceptibility sum rules; (ii) keep account of kinetic correlations by means of an integration over the coupling strength; and (iii) provide a practical self-consistent scheme for evaluating linear response and liquid structure. Numerical illustrations are given for the dielectric response of the paramagnetic electron gas in both three and two dimensions.Comment: 9 pages, 3 figures, submitted to Solid State Commu

Pair densities at contact in the quantum electron gas

The value of the pair distribution function g(r) at contact (r = 0) in a quantum electron gas is determined by the scattering events between pairs of electrons with antiparallel spins. The theoretical results for g(0) as a function of the coupling strength r_s in the paramagnetic electron gas in dimensionality D=2 and 3, that have been obtained from the solution of the two-body scattering problem with a variety of effective scattering potentials embodying many-body effects, are compared with the results of many-body calculations in the ladder approximation and with quantum Monte Carlo data.Comment: 7 pages, 2 figure

Plasmon dispersion and damping in double-layer electron systems

Cataloged from PDF version of article.We use dynamical local-field corrections to study the plasmon dispersion and damping in double-layer electron systems. The wave vector and frequency-dependent local-fields describing the exchange-correlation effects are obtained within the quantum version of self-consistent field approach. The calculated plasmon dispersions are modified by the dynamic local-fields at intermediate wave vectors (i.e. q similar to k(F)) The plasmons are damped outside the single-particle excitation region. (C) 2000 Elsevier Science Ltd. All rights reserved

Self-consistent Overhauser model for the pair distribution function of an electron gas at finite temperature

We present calculations of the spin-averaged pair distribution function $g(r)$ in a homogeneous gas of electrons moving in dimensionality D=3 or D=2 at finite temperature. The model involves the solution of a two-electron scattering problem via an effective potential which embodies many-body effects through a self-consistent Hartree approximation, leading to two-body wave functions to be averaged over a temperature-dependent distribution of relative momentum for electron pairs. We report illustrative numerical results for $g(r)$ in an intermediate-coupling regime and interpret them in terms of changes of short-range order with increasing temperature.Comment: 6 pages, 5 figures, submitted to Solid State Communication