Abstract
Out-of-time-order correlators (OTOCs), recently at the center of discussion on quantum chaos, are tools to understand the information scrambling in different phases of quantum many-body systems. We propose a disordered ladder spin model, the XX ladder, which can be designed in a scalable cold atom setup to detect OTOCs with a sign reversal protocol alternative to existing approaches for evolution backward in time. We study both the clean and disordered XX ladder and characterize different phases (ergodic and many-body localized phases) of the model based on the decay properties of OTOCs. The emergent effective lightcone shows sublinear behavior, while the butterfly cones drastically differ from the lightcone via demonstrating superlinear behavior. Based on our results, one can observe how the information scrambling changes in the transition from well-studied one-dimensional spin models to unexplored two-dimensional spin models in a local setting.
5 More- Received 28 August 2018
DOI:https://doi.org/10.1103/PhysRevA.99.052322
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