Abstract

It is shown that the correlation effects on a twodimensional electron gas in a uniform perpendicular magnetic field are significantly affected by a strong magnetic field. A dielectric function approach is used to go beyond the RPA by improving the effective potential. This is done by including the local field correction Gq to the mean Hartree field. Following Singwi et al. we replace the twoparticle distribution function f2(r, p; r′, p′; t) by a product of two equilibrium oneparticle distribution functions f(r, p; t)f(r′, p′; t) g(r  r′), where g(r) is the static equilibrium pair correlation function. We have shown that the form of the effective potential is not altered by a uniform magnetic field. Both Gq and the pair correlation function oscillate as functions of the magnetic field. The local field correction has maxima at halfodd integer fillings and minima at integer filling factors. As a result, the effective interparticle potential has enhanced oscillations. The effect due to correlations on the plasma excitations is also discussed. © 1993 Academic Press, Inc.