Electronic and dynamic properties of a one-dimensional Thue-Morse chain

TL;DR

This study investigates the electronic and dynamic properties of a one-dimensional Thue-Morse chain, revealing extended electronic states and superdiffusive wave packet spreading, with effects of electron-phonon interactions analyzed.

Contribution

It demonstrates that all electronic states are extended in the Thue-Morse chain and explores the wave packet dynamics and electron-phonon interactions, contrasting previous findings.

Findings

Electronic states are extended despite singular spectrum.

Wave packets spread superdiffusively over long times.

Electron-phonon interactions influence dynamic localization.

Abstract

We study the electronic and dynamic properties of a one-dimensional Thue-Morse chain within the framework of the transfer model. By means of direct diagonalization of the Hamiltonian matrix we first show that the trace map of the transfer matrices is exactly the same as that in the diagonal model. Then, by calculating several quantities such as the wave function, the Lyapunov exponent, and the Landauer resistivity, we show that all the electronic states are extended despite the singular continuity of the energy spectrum. Our results indicate that the electronic properties of the Thue-Morse chain is independent of the kind of the model, which is contrary to the result of Chakrabarti et al. [Phys. Rev. Lett. 74, 1403 (1995)]. To deepen our understanding, we study the dynamics of an electronic wave packet and show that the wave packet spreads superdiffusively for long times with dynamic indices intermediate between periodic and quasiperiodic chains. Several features of dynamics distinctive from the case of the Fibonacci chain are discussed. We also study the effects of electron-phonon interaction on the dynamics of the wave packet by taking into account a kind of nonlinear interaction. Degree of dynamic localization is shown to be crucially dependent on the strength of the hopping energy and the nonlinear interaction parameter.