Stripe stability in the extended t-J model on planes and four-leg ladders

The tendencies to phase-separation and stripe formation of the t-J model on planes and four-leg ladders have been here reexamined including hole hoppi ng terms t',t " beyond nearest-neighbor sites. The motivation for this stud y is the growing evidence that such terms are needed for a quantitative des cription of the cuprates. Using a variety of computational techniques it is concluded that the stripe tendencies considerably weaken when experimental ly realistic t'<0, t ">0 for hole-doped cuprates are considered. However, a small t'>0 actually enhances the stripe formation. [S0163-1829(99)51218-6] .