Abstract
Electromagnetic radiation originating with localized surface plasmons in the metal-tip/metal-sample nanocavity of a scanning tunneling microscope is demonstrated to extend to a wavelength λ of at least 1.7 μm. Progressive spectral extension beyond λ ∼ 1.0 μm occurs for increasing tip radius above ∼ 15 nm, reaching λ ∼ 1.7 μm for tip radius ∼ 100 nm; these observations are corroborated by use of a simple physical model that relates the discrete plasmon mode frequencies to the tip radius. This spectral extension opens up a new regime for scanning tunneling microscope-based optical spectroscopy.
Original language | English |
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Article number | 233118 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 94 |
Issue number | 23 |
DOIs | |
Publication status | Published - 12 Jun 2009 |
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)