Out-of-time-order correlators in the one-dimensional XY model

Jia-Hui Bao,Cheng-Yong Zhang

Figure 4. Fitting of the universal form and numerical data of Czz. We select three models with different vB to confirm whether the conjecture holds in the XY model. The dots represent numerical data from the OTOC along velocity-fixed rays, where v = 1.1, 1.2, and 1.5, respectively. The solid lines are fitting forms of −at + b. Coefficient a is the velocity-dependent Lyapunov exponents λL(v) that we need to extract. The insets show the three sets of extracted data fitted by $\sim {(v-{v}_{B})}^{1+p}$. We note that the numerical data fits quite well.