Subharmonic Fidelity Revival of the Driven PXP model

Recenrtly, PXP model has been studied as an example of the quantum scar, which contains a small portion of non-thermal eigenstates. This non-thermalness can be measured by the fidelity revival starting from certain pure state, which is also a key phenomenon in the quantum scar system. It has been reported that the temporal driving of the PXP model with certain amplitude enhances the fidelity revival. In this work, we show that the driven PXP model contains a subharmonic fidelity revival also. With free spin chain model, we have explained the origin of this subharmonic fidelity revival.