Long-range effects on optical absorption in quasiperiodic lattices

TL;DR

This paper investigates how quasiperiodic order in lattices affects exciton optical absorption spectra, revealing characteristic features and developing an analytical method to relate spectral satellites to the lattice's Fourier pattern.

Contribution

It introduces an analytical approach linking satellite lines in absorption spectra to the Fourier pattern of quasiperiodic lattices, enhancing understanding of long-range order effects.

Findings

Quasiperiodic order causes distinct features in absorption spectra.

An analytical method relates satellite lines to the lattice's Fourier pattern.

Predictions enable experimental determination of quasiperiodic order.

Abstract

We consider exciton optical absorption in quasiperiodic lattices, focusing our attention on the Fibonacci case as typical example. The absorption spectrum is evaluated by solving numerically the equation of motion of the Frenkel-exciton problem on the lattice, in which on-site energies take on two values according to the Fibonacci sequence. We find that the quasiperiodic order causes the occurrence of well-defined characteristic features in the absorption spectra. We also develop an analytical method that relates satellite lines with the Fourier pattern of the lattice. Our predictions can be used to determine experimentally the long-range quasiperiodic order from optical measurements.