We present the results of analytical evaluation of the indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in a layered metal with nearly nested (almost square) Fermi surface. The final expressions are obtained in closed form as a combination of Bessel functions. We discuss the notion of the “${2k}_F$” oscillations and show that they occur as the far asymptote of our expressions. We show the existence of the intermediate asymptote of the interaction which is of the sign-reversal antiferromagnetic type and is the only term surviving in the limit of exact nesting. A good accordance of our analytical formulas with numerical findings is demonstrated until the interatomic distances. The expressions obtained for the Green’s functions extend the previous analytical results into the region of intermediate distances.

• Received 19 June 1997

DOI:https://doi.org/10.1103/PhysRevB.56.8841