Abstract
By making use of the renormalized mean-field theory, we investigate possible superconducting symmetry in the ground states of the t1-t2-J1-J2 model on a square lattice. The superconducting symmetry of ground states is determined by the frustration amplitude t2/t1 and doping concentration. The phase diagram of this system in the frustration-doping plane is given. The amplitude of the pairing parameter on diagonal bonds increases with increasing value of t2/t1, and ground-state change from a conventional dx2−y2-wave state to a mixed state, ultimately to a dxy-wave state. The order of the phase transitions among these different symmetry states is discussed.