Exciton Optical Absorption in Self-Similar Aperiodic Lattices

Abstract

Exciton optical absorption in self-similar aperiodic one-dimensional systems is considered, focusing our attention on Thue-Morse and Fibonacci lattices as canonical examples. The absorption line shape is evaluated by solving the microscopic equations of motion of the Frenkel-exciton problem on the lattice, in which on-site energies take on two values, according to the Thue-Morse or Fibonacci sequences. Results are compared to those obtained in random lattices with the same stechiometry and size. We find that aperiodic order causes the occurrence of well-defined characteristic features in the absorption spectra which clearly differ from the case of random systems, indicating a most peculiar exciton dynamics. We successfully explain the obtained spectra in terms of the two-center problem. This allows us to establish the origin of all the absorption lines by considering the self-similar aperiodic lattices as composed of two-center blocks, within the same spirit of the renormalization group ideas.

16 pages in REVTeX 3.0. 2 figures on request to F. D-A ([email protected])

References in corpus (2)

• Energy spectra of quasiperiodic systems via information entropy
• Optical absorption in paired correlated random lattices

Cited by in corpus (7)

• Physical nature of critical wave functions in Fibonacci systems
• Remarks on the Spectral Properties of Tight Binding and Kronig-Penney Models with Substitution Sequences
• Fluorescence decay in aperiodic Frenkel lattices
• X-Ray Reflectivity of Fibonacci Multilayers
• Incoherent Exciton Trapping in Self-Similar Aperiodic Lattices
• Long-range effects on optical absorption in quasiperiodic lattices
• Optical absorption in Fibonacci lattices at finite temperature