Polaronic quantum diffusion in dynamic localization regime

TL;DR

This paper explores quantum diffusion in a disordered lattice with electron-phonon interactions, revealing a transition from static to dynamic localization and demonstrating coherent polaron diffusion unaffected by disorder.

Contribution

It introduces a novel understanding of polaronic quantum diffusion in disordered systems, highlighting a transition to dynamic localization and the persistence of diffusion despite energy disorder.

Findings

Transition from static to dynamic localization indicated by inverse participation ratio slope change

Coherent polaron diffusion occurs via hopping-like processes in the dynamic localization regime

Quantum diffusion persists despite strong energy disorder in the system

Abstract

We investigate the quantum dynamics in a disordered electronic lattice with Fibonacci sequence of site energy and off-diagonal electron-phonon coupling within a sub-Ohmic bath by the time-dependent density matrix renormalization group algorithm. It is found that, the slope of the inverse participation ratio versus the coupling strength undergoes a sudden change indicating a transition from the static to the dynamic localization. In the dynamic localization regime, the generated polarons coherently diffuse via hopping-like processes evidenced by the saturated entanglement entropy, providing a novel scenario for the transportation mechanism in strongly disordered systems. The mean-square displacement is revealed to be insensitive to the coupling strength, implying the quantum diffusion behavior survives the energy disorder that prevails in real organic materials.