Shortranged correlations and the ferromagnetic electron gas
Abstract
A discussion of the various properties of pair correlation functions of a magnetic electron gas is presented. The cusp conditions obeyed by the manyelectron wave functions for a pair of electrons with parallel and antiparallel spins in close proximity are expressed as derivative conditions on the corresponding paralleland antiparallelspin pair correlation functions. In particular, it is shown that in a fully ferromagnetic gas the parallel spin correlations determine the correlation energy whereas in the paramagnetic case, this function is of less importance in comparison to the antiparallelspin correlation function. In the highmomentum limit, it is found that the momentum distribution of electrons is dominated by antiparallelspin correlations in the partially magnetic case whereas in the fully ferromagnetic case, it is dominated by parallelspin correlations but is smaller by a factor of q^{2}. A calculation of the parallelspin correlation function for the ferromagnetic gas in perturbation theory is presented. A model for the exchange correlation energy of the system which takes into account the exact conditions given here is proposed. Corresponding results for the twodimensional electron gas are also stated.
 Publication:

Physical Review B
 Pub Date:
 September 1978
 DOI:
 10.1103/PhysRevB.18.2339
 Bibcode:
 1978PhRvB..18.2339R