Bethe ansatz approach for the steady state of the asymmetric simple exclusion process with open boundaries

We study the asymmetric simple exclusion process with nondiagonal boundary terms under a specific constraint. A symmetric chiral basis is constructed and a special string solution of the Bethe ansatz equations corresponding to the steady state is presented. Using the coordinate Bethe ansatz method, we derive a concise expression for the steady state. The current and density profile in the steady state are also studied.