Dual mapping and quantum criticality in quasiperiodic Su-Schrieffer-Heeger chains

We study a class of off-diagonal quasiperiodic hopping models described by a one-dimensional Su-Schrieffer-Heeger chain with quasiperiodic modulations. With regard to these models, we unveil a general dual-mapping relation in parameter space of the dimerization strength $\ensuremath{\lambda}$ and the quasiperiodic modulation strength $V$, regardless of specific details of quasiperiodic modulations. Moreover, we demonstrated semianalytically and numerically that under the specific quasiperiodic modulation, quantum criticality, namely the criticality of wave functions, can emerge and persist in a wide parameter space. These unusual results provide a distinctive paradigm compared with the diagonal quasiperiodic systems and perspectives for future investigations on quasiperiodic disorder.