Relativistic electron energy loss spectroscopy of solid and core-shell nanowires

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.81.165403· OSTI ID:21366735

Hyun, J K; Levendorf, M P; Blood-Forsythe, M; Park, J; Muller, D A ^[1]

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1. Department of Physics, Cornell University, Ithaca, New York 14853 (United States)

Near-field optical spectroscopy with nanometer spatial resolution using transition radiation from a focused, relativistic electron beam is demonstrated for Ge nanowires. The excitation of the waveguide modes is absent in theoretical treatments that neglect retardation because the coupling of the swift electron to the optical modes of the nanowire is a consequence of its relativistic nature. Here, relativistic energy loss probabilities for aloof electron trajectories near a perpendicularly oriented single nanowire are analytically calculated using a local dielectric theory. Multimode and zero-mode Ge nanowires are experimentally measured in this geometry with a approx2-nm-size electron probe. Observations fall in excellent agreement with the retarded calculations. Optical eigenmodes are identified from comparison of the experimental electron energy loss spectra to theoretical dispersion maps. Adding a Drude-type metallic shell to a dielectric nanowire provides surface-plasmon modes in the same energy range as the dielectric waveguide, leading to strongly coupled hybrid modes that can be efficiently excited by the incident electron. Such results demonstrate a powerful solution for optical studies of nanosystems with nanometer spatial resolution over a broadband energy range.

• OSTI ID: 21366735
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 81, Issue 16; Other Information: DOI: 10.1103/PhysRevB.81.165403; (c) 2010 The American Physical Society; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
COMPARATIVE EVALUATIONS
COUPLING
DIELECTRIC MATERIALS
ELECTRON BEAMS
ENERGY LOSSES
ENERGY-LOSS SPECTROSCOPY
EXCITATION
GERMANIUM
OPTICAL MODES
QUANTUM WIRES
RELATIVISTIC RANGE
SOLIDS
SPATIAL RESOLUTION
SURFACES
TRANSITION RADIATION
WAVEGUIDES
BEAMS
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EVALUATION
LEPTON BEAMS
LOSSES
MATERIALS
METALS
NANOSTRUCTURES
OSCILLATION MODES
PARTICLE BEAMS
RADIATIONS
RESOLUTION
SPECTROSCOPY