  Recently a phenomenological Ginzburg-Landau (GL) theory has been proposed to
describe the occurrence of a locally time-reversal symmetry (T) breaking state
near a Josephson junction between unconventional superconductors. In this paper
we derive this type of GL free energy microscopically from the t-J model within
a slave-boson mean-field approximation. The resulting GL free energy is shown
to satisfy the conditions to have a T-violating surface state. The existence of
this junction state may explain some of the recent experiments on High-Tc
superconductors.
