In my talk I will discuss a new mechanism of the weak ergodicity breaking relevant for the experimentally realized Rydberg-atom quantum simulators . This mechanism arises from the presence of special eigenstates in the many-body spectrum that are reminiscent of quantum scars in chaotic non-interacting systems . After review of different mechanisms that lead to scars, I will discuss more recent experiments  that demonstrated that coherent revivals associated with quantum many-body scars can be stabilized by periodic driving, generating stable subharmonic responses over a wide parameter regime. I will propose a simple model which explains experimental phenomena by spatiotemporal ordering in an effective Floquet unitary, corresponding to discrete time-crystalline (DTC) behavior in a prethermal regime. Unlike conventional DTC, the subharmonic response exists only for Neel-like initial states, associated with quantum scars. I will discuss robustness to perturbations and identify emergent timescales that could be observed in future experiments.
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