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 (B). 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 √B dependence, while those of a bilayer ribbon exhibit a varying B-field dependence. In the spectra region ω≤100 meV, the absorption frequencies of Landau peaks are linearly dependent on the magnetic-field magnitude. At ω≥100 meV, they evolve from the B dependence to the √B dependence with the increase in the field strength. The absorption frequencies of Landau peaks exhibit √B dependence at B≥20 T. 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.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2008 Sep 22|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics