Spin liquid in an almost ferromagnetic Kondo lattice

A theory of stabilization of a spin liquid in a Kondo lattice at temperatures close to the temperature of antiferromagnetic instability has been developed. Kondo exchange scattering of conduction electrons leads to emergence of a state of the spin liquid of the resonating valence bonds (RVB) type at T>T _K. Owing to this stabilization, low-energy processes of Kondo scattering with energies below T _K are frozen so that the “singlet” state of the Kondo lattice is not realized; instead a strongly correlated spin liquid with developed antiferromagnetic fluctuations occurs. A new version of the Feynman diagram technique has been developed to describe interaction between spin fluctuations and resonant valence bonds in a self-consistent manner. Emergence of a strongly anisotropic RVB spin liquid is discussed. Zh. éksp. Teor. Fiz. 112, 729–759 (August 1997)