  We investigate the non-nearest-neighbor interaction effect in 1-D spin-1/2
chain model. In many previous schemes this long-range coupling is omitted
because of its relative weak strength compared with the nearest-neighbor
coupling. We show that the quantum gate deviation induced by the omitted
long-range interaction depends on not only its strength but also the scale of
the system. This implies that omitting the long-range interaction may challenge
the scalability of previous schemes. We further consider how to suppress this
unwanted effect. We propose a quantum computation scheme. In this scheme, by
using appropriate encoding method, we effectively negate the influence of the
next-nearest-neighbor interaction in order to improve the precision of quantum
gates. We also discuss the feasibility of this scheme in 1-D Josephson charge
qubit array system. This work may offer improvement in scalable quantum
computing.
