Dispersion of the π resonance in the superconducting state of the cuprates -: art. no. 100502

We study the dispersion of tr resonance in the superconducting state within the projected SO(5) model [S.C. Zhang et al., Phys. Rev. B 60, 13 070 (1999)]. Away from the commensurate momentum, the propagation of the pi resonance creates phase flips in the superconducting order parameter. This frustration effect leads to a strong dressing of the pi resonance and a downward dispersion away from the commensurate wave vector. Based on these results, we argue that the commensurate resonance and incommensurate magnetic fluctuations in the cuprates are continuously connected.