Out-of-time-order correlators in the one-dimensional XY model
Jia-Hui Bao, Cheng-Yong Zhang
Abstract We study the behavior of information spreading in the XY model, using out-of-time-order correlators (OTOCs). The effects of anisotropic parameter γ and external magnetic field λ on OTOCs are studied in detail within thermodynamical limits. The universal form which characterizes the wavefront of information spreading still holds in the XY model. The butterfly speed v B depends on ( γ , λ ). At a fixed location, the early-time evolution behavior of OTOCs agrees with the results of the Hausdorff–Baker–Campbell expansion. For long-time evolution, OTOCs with local operators decay as for power law t −1 , but those with nonlocal operators show different and nontrivial power law behaviors. We also observe temperature dependence for OTOCs when ( γ = 0, λ = 1). At low temperature, the OTOCs with nonlocal operators show divergence over time.
arXiv:1901.09327•Communications in Theoretical Physics•Jul 20, 2020•14 citations