THE IMPACT OF THE CONCEPT OF A SURFACE-PLASMON

Significant progress has been made in understanding the physical natur e of collective excitations at a surface since the concept of a surfac e plasmon was introduced 37 years ago by Ritchie [Phys. Rev. 106 (1957 ) 874]. The development of our understanding of surface plasmons and h igher order modes will be discussed, and the impact of this concept on a wide range of phenomena will be presented. The concept of a surface plasmon coupled with the basic understanding that has been achieved i s having an impact on a variety of fields, such as size dependence in the Mie resonance in clusters and plasmon excitations in quantum wells .