Weak antiferromagnetism in the Kondo lattice

The N-fold degenerate Anderson model for a lattice is considered in the Kon do-regime. The system of f-electrons is supposed to be extremely correlated (U --> infinity). Using a slave boson approach and a 1/N expansion a crite rion of the spin density wave (SDW) instability in the system of itinerant electrons is obtained. An effective interaction resulting in the SDW being formed appears due to spin fluctuations in the system of localized electron s. (C) 1999 Elsevier Science B.V. All rights reserved.