Abstract
We study a periodically driven central site coupled to a disordered environment. In comparison to the static model, transport features are either enhanced or reduced, depending on the frequency of the drive. We demonstrate this by analyzing the statistics of quasienergies and the logarithmic growth of bipartite entanglement entropy, which show similar features: For frequencies larger than disorder strength, localization is enhanced due to a reduced effective coupling to the central site. Remarkably, localization can even be increased up to almost perfect freezing at particular frequencies, at which the central site decouples due to the emergence of “dark Floquet states.” This high-frequency domain of our model is bounded from below by a critical frequency , at which transport increases abruptly. We demonstrate that is determined by one-photon resonances, which connect states across the mobility edge and generically delocalize the system. This sensitive frequency dependence allows us to fine-tune transport properties of the driven central-site model with unprecedented precision.
- Received 7 February 2019
- Revised 27 June 2019
DOI:https://doi.org/10.1103/PhysRevB.100.014201
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