FLUX BINDING AND SUPERCONDUCTIVITY IN THE T-J MODEL

A generalized slave-particle scheme is introduced to study the t-J mod el with nonlocal effects included. A charge-spin decoupled state is fo und in this scheme, in which the nonlocal gauge fields play a role of attaching fictitious quantized fluxes to the particles as an effective way to describe antiferromagnetic correlation. As a result, the gauge fluctuation is suppressed in the long-wavelength limit, which shows t he stability of flux binding, and the electromagnetic response functio n of such a state exhibits the Meissner effect. An important consequen ce of the present approach is that the electron, as a combination of t he charge and spin degrees of freedom, does not show time-reversal and parity-symmetry-broken behavior, in contrast to the usual anyon theor y. This is consistent with experimental results. The robustness of thi s conclusion relies on the exactness of the constraint between the cha rge and spin degrees of freedom as well as the flux binding condition. We also calculate the momentum distribution of electrons, which shows a characteristic scale equal to the Fermi momentum k(f).