  Within the fermion-spin theory, the physical properties of the electron
pairing state in the copper oxide materials are discussed. According to the
common form of the electron Cooper pair, it is shown that there is a
coexistence of the electron Cooper pair and magnetic short-range correlation,
and hence the antiferromagnetic short-range correlation can persist into the
superconducting state. Moreover, the mean-field results indicate that the
electron pairing state originating from the pure magnetic interaction in the
two-dimensional t-J model is the local state, and then does not reveal the true
superconducting ground-state.
