Magnetic Properties of Quasi-Two Dimensional Antiferromagnetic Spins Interacting with Itinerant Electrons

Abstract

The magnetic properties of the quasi-two dimensional antiferromagnetic spins interacting with the itinerant electrons through the Kondo coupling are investigated. In the normal state, the dynamical susceptibility χ⁻⁺ (q,w), the decay rate of the magnon Γq, and the NMR relaxation rate T₁ ⁻¹ are calculated up to second order in the perturbation. It is found that Γq has a non-vanishing value at q → 0. It is also found that the major contribution to T ₁ ⁻¹ comes from the susceptibilities at around the antiferromagnetic wave vector Q, and T₁ ⁻¹ is proportional to T at low temperatures and is proportional to T ⁻¹ at high temperatures.