@article{WOS:000559925200003,
 abstract = {We study the dynamics of a periodically driven Rydberg chain starting
from the state with zero Rydberg excitations (vacuum state denoted by
vertical bar 0 >) using a square pulse protocol in the high drive
amplitude limit. We show, using exact diagonalization for finite system
sizes (L <= 26), that the Floquet Hamiltonian of the system, within a
range of drive frequencies that we chart out, hosts a set of quantum
scars that have large overlap with the vertical bar 0 > state. These
scars are distinct from their counterparts having high overlap with the
maximal Rydberg excitation state (vertical bar Z(2)>); they coexist with
the latter class of scars and lead to persistent coherent oscillations
of the density-density correlator starting from the vertical bar 0 >
state. We also identify special drive frequencies at which the system
undergoes perfect dynamic freezing, and we provide an analytic
explanation for this phenomenon. Finally, we demonstrate that for a wide
range of drive frequencies, the system reaches a steady state with
subthermal values of the density-density correlator. The presence of
such subthermal steady states, which are absent for dynamics starting
from the vertical bar Z2 > state, imply a weak violation of the
eigenstate thermalization hypothesis in finite-sized Rydberg chains
distinct from that due to the scar-induced persistent oscillations
reported earlier. We conjecture that in the thermodynamic limit, such
states may exist as prethermal steady states that show anomalously slow
relaxation. We supplement our numerical results by deriving an analytic
expression for the Floquet Hamiltonian using a Floquet perturbation
theory in the high amplitude limit, which provides an analytic, albeit
qualitative, understanding of these phenomena at arbitrary drive
frequencies. We discuss experiments that can test our theory.},
 article-number = {075123},
 author = {Mukherjee, Bhaskar and Sen, Arnab and Sen, Diptiman and Sengupta, K.},
 doi = {10.1103/PhysRevB.102.075123},
 eissn = {2469-9969},
 issn = {2469-9950},
 journal = {PHYSICAL REVIEW B},
 month = {AUG 17},
 number = {7},
 orcid-numbers = {Mukherjee, Bhaskar/0000-0003-0919-9362},
 title = {Dynamics of the vacuum state in a periodically driven Rydberg chain},
 unique-id = {WOS:000559925200003},
 volume = {102},
 year = {2020}
}