We consider the inverse coefficient problem of simultaneously determining the space dependent electric potential, the zero-th order coupling term and the first order coupling vector of a two-state Schrödinger equation in an infinite cylindrical domain of R n , n≥2, from finitely many partial boundary measurements of the solution. We prove that these n+3 unknown scalar coefficients can be Hölder stably retrieved by ( n+1)-times suitably changing the initial condition attached at the system.