The ground state properties of the S = 1/2 antiferromagnetic XY model with quasiperiodic modulation

The low-energy properties of the S = 1/2 antiferromagnetic XY model with quasiperiodic modulation are investigated for the consideration of spin-phonon coupling. It is found that the lattice distortion at every site displays a self-similar character, which is induced by quasiperiodic modulation. As quasiperiodic modulation is strengthened, the average lattice distortion may decrease and increase for strong and weak enough spin-phonon coupling, respectively. Correspondingly, the scaling behavior of the energy gap in this system is also strongly dependent on the spin-phonon coupling.