Rights statement: © 2010 The American Physical Society
Final published version, 226 KB, PDF document
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Article number | 045405 |
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<mark>Journal publication date</mark> | 8/07/2010 |
<mark>Journal</mark> | Physical review B |
Issue number | 4 |
Volume | 82 |
Number of pages | 7 |
Publication Status | Published |
<mark>Original language</mark> | English |
We investigate the contribution of the low-energy electronic excitations toward the Raman spectrum of bilayer graphene for the incoming photon energy Omega greater than or similar to 1 eV. Starting with the four-band tight-binding model, we derive an effective scattering amplitude that can be incorporated into the commonly used two-band approximation. Due to the influence of the high-energy bands, this effective scattering amplitude is different from the contact interaction amplitude obtained within the two-band model alone. We then calculate the spectral density of the inelastic light scattering accompanied by the excitation of electron-hole pairs in bilayer graphene. In the absence of a magnetic field, due to the parabolic dispersion of the low-energy bands in a bilayer crystal, this contribution is constant and in doped structures has a threshold at twice the Fermi energy. In an external magnetic field, the dominant Raman-active modes are the n(-) -> n(+) inter-Landau-level transitions with crossed polarization of in/out photons. We estimate the quantum efficiency of a single n(-) -> n(+) transition in the magnetic field of 10 T as In- (n+) similar to 10(-12).