| Sažetak (engleski) | Using our recently proposed Bethe-Salpeter G_0W_0 formulation, we explore the optical absorption spectra of fullerene (C_60) near coinage metal surfaces (Cu, Ag, and Au). We pay special attention to how the surface plasmon ω_S influences the optical activity of fullerene. We find that the lower-energy fullerene excitons at 3.77 and 4.8 eV only weakly interact with the surface plasmon. However, we find that the surface plasmon strongly interacts with the most intense fullerene π exciton, i.e., the dipolar mode at ℏω+≈6.5 eV, and the quadrupolar mode at ℏω−≈6.8 eV. When fullerene is close to a copper surface (z_0≈5.3 Å), the dipolar mode ω_+ and “localized” surface plasmons in the molecule/surface interface hybridize to form two coupled modes which both absorb light. As a result, the molecule gains an additional optically active mode. Moreover, in resonance, when ω_S≈ω_±, the strong interaction with the surface plasmon destroys the ω− quadrupolar character and it becomes an optically active mode. In this case, the molecule gains two additional very intense optically active modes. Further, we find that this resonance condition, ω_S≈ω_±, is satisfied by silver and gold metal surfaces. |
