We investigate quantum dynamics with the underlying Hamiltonian being a Jacobi or a block Jacobi matrix with the diagonal and the off-diagonal terms modulated by a periodic or a limit-periodic sequence. In particular, we investigate the transport exponents. In the periodic case we demonstrate ballistic transport, while in the limit-periodic case we discuss various phenomena such as quasi-ballistic transport and weak dynamical localization. We also present applications to some quantum many body problems. In particular, we establish for the anisotropic XY chain on $\mathbb{Z}$ with periodic parameters an explicit strictly positive lower bound for the Lieb-Robinson velocity.
翻译:我们调查量子动态,其基础的汉密尔顿座右铭是雅各比或雅各比矩阵块,带有对角和对角外术语,以定期或限时顺序调节;特别是,我们调查运输前导体;在定期案例中,我们展示弹道运输;而在定期案例中,我们讨论各种现象,如准弹道运输和弱的动态定位;我们还对一些数量众多的体质问题提出应用;特别是,我们为定期参数的厌食XY链以美元为单位,为Lieb-Robinson速度设定一个绝对正下限。