Abstract
We consider a chain described by a next-nearest-neighbor hopping combined with a nearest-neighbor spin flip. In two dimensions this three-body term arises from a mapping of the three-band Hubbard model for CuO
2
planes to a generalized
t−J
model and for large O-O hopping favors resonance-valence-bond superconductivity of predominantly
d
-wave symmetry. Solving the ground state and low-energy excitations by analytical and numerical methods we find that the chain is a Luther-Emery liquid with correlation exponent
K
ρ
=(2−n
)
2
/2
, where
n
is the particle density.