Naslov
Using surface plasmonics to turn on fullerene’s dark excitons

Autori
Despoja, Vito ; Mowbray, Duncan

Izvornik
Physical Review B - Condensed Matter and Materials Physics (1098-0121) 89 (2014); 195433-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Fullerene; optical absorption; GW-BSE; surface plasmons

Sažetak
Using our recently proposed Bethe-Salpeter G0 W0 formulation, we explore the optical absorption spectra of fullerene (C60 ) near coinage metal surfaces (Cu, Ag, and Au). We pay special attention to how the surface plasmon ωS 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 ω+ ≈ 6.5 eV, and the quadrupolar ̊ mode at ω− ≈ 6.8 eV. When fullerene is close to a copper surface (z0 ≈ 5.3 A), 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 ωS ≈ 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, ωS ≈ ω± , is satisfied by silver and gold metal surfaces.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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