Role of virtual states and localized-delocalized transition on excitation injection of surface sites: Applications to plasmonic.

RAÚL A. BUSTOS MARÚN; EDUARDO A. CORONADO; HORACIO M. PASTAWSKI

Salinas de Maragogi, Brasil.

Simposio; 20th Latin American Symposium on Solid State Physics (SLAFES XX), Salinas de Maragogi, Brasil.; 2011

In this work we analyze the role of virtual states and localized-delocalized transition on injection and transport of excitations from a surface site to the interior of a semi-infinite chain [1, 2]. We focus on a plasmonic system which consists of a one dimension semi-infinite linear array of small nanoparticles (NPs) where we study the plasmonic energy transfer from a locally excited NP at the end of the array, to its interior [2]. The system is modeled as a set of coupled dipoles with interactions in a near field approximation, which is justified when NPs are sufficiently small compared with excitation wavelengths and if the separation between NPs is not too small compared with their radii [3]. Under these conditions the physics of the system is equivalent to that of an array of damped harmonic oscillators [4] and similar to some quantum mechanical models [2, 5]. In particular, we present, through a detailed analysis of the response function’s poles, a parameter’s phase space diagram which allows one to fully characterize the system behavior at any condition. Moreover, we discuss the intriguing question of ”why a non-physical pole of the response function, such as a virtual state, becomes high relevant in this case”, and the pragmatic one of ”howto use the extreme sensitivity of the localized-delocalized transition on the system’s parameters, to different plasmonic applications”.[1]  A.D. Dente, R.A. Bustos-Mar ́n, and H.M. Pastawski, Phys. Rev. A 78, 062116 (2008). [2] R. A. Bustos-Marun, E. A. Coronado, and H. M. Pastawski., Phys. Rev. B 82, 035434 (2010).[3] M. L. Brongersma, J. W. Hartman, and H. A. Atwater, Phys. Rev. B 62, R16356 (2000).[4] L. A. Sweatlock, S. A. Maier, H. A. Atwater, Proceedings - Electronic Components and Technology Conference, 1648 (2003);H.L. Calvo, E. P. Danieli, H. M. Pastawski, Phys. B 398, 317 (2007); L. Gutierrez et al., Phys. Rev. Lett. 97, 114301 (2006)[5] D. M. Newns, Phys. Rev. 178, 1123 (1969); E. Santos, M.T.M. Koper and W. Schmickler, Chem. Phys. Lett. 419, 421(2006).