  We present numerical evidence for the existence of a staggered flux (SF)
phase in the half-filled two-leg t-U-V-J ladder, with true long-range order in
the counter-circulating currents. The density-matrix renormalization-group
(DMRG) / finite-size scaling approach, generalized to describe complex-valued
Hamiltonians and wavefunctions, is employed. The SF phase exhibits robust
currents at intermediate values of the interaction strength.
