Strongly correlated electrons: the t-J model
Mikheev Institute of Metal Physics, Ural Division of the Russian Academy of Sciences, S Kovalevskoi str. 18, Ekaterinburg, 620108, Russian Federation
A systematic study is made of the t-J model as a working model for copper oxide high-Tc superconductors. The main focus is on the near-half- filling region (low hole concentrations) relevant to these materials. The theory of the magnetic polaron, which is a charge carrier traveling in an antiferromagnetic matrix, and the theory of antiferromagnetic ordering are discussed in a unified framework. The spin liquid state beyond the antiferromagnetic phase is examined. The Hamiltonian parameters — hole concentration phase diagram for the model is described and compared with that for the Hubbard model in the strong correlation limit. Two extensions of the t-J model, the t-t’-J model and the three-center interaction model, are discussed. Mostly analityc strong correlation techniques are employed in this review.