Abstract
Magnetoabsorption spectra of bilayer graphene ribbons with Bernal stacking are studied by the Peierls-coupling tight-binding method. When the magnetic confinement prevails over the quantum confinement, low-energy spectra chiefly exhibit many Landau peaks, which are strongly modified by the inter-ribbon interactions and the magnetic-field magnitude . The spectra show denser Landau peaks in bilayer graphene ribbon than in a monolayer ribbon with the same ribbon width. The absorption frequencies of Landau peaks of a wide monolayer ribbon show the dependence, while those of a bilayer ribbon exhibit a varying -field dependence. In the spectra region , the absorption frequencies of Landau peaks are linearly dependent on the magnetic-field magnitude. At , they evolve from the dependence to the dependence with the increase in the field strength. The absorption frequencies of Landau peaks exhibit dependence at . The relationship between the magneto-optical properties and electronic structures (the state energies and wave functions) are explored. The Landau wave functions are illustrated and used to identify the optical selection rule.
- Received 16 May 2008
DOI:https://doi.org/10.1103/PhysRevB.78.115422
©2008 American Physical Society