Squeezing THz light into nanovolumes
We show that chains of THz dipole nanoantennas spaced by nanogaps of 20 nm allow retrieving the spectroscopic signature of a monolayer of cadmium selenide quantum dots
A. Toma et al., Nano Letters 15, 386 (2015)
| THz spectroscopy has vast potentialities in sensing a broad range of elementary excitations but the large wavelengths associated with THz radiation severely hinders its interaction with nano-objects, practically limiting THz studies to macroscopic ensembles of these compounds. here we show that chains of THz dipole nanoantennas spaced by nanogaps of 20 nm allow retrieving the spectroscopic signature of a monolayer of cadmium selenide quantum dots. A Fano-like interference between the fundamental antenna mode and the phonon resonance of the quantum dot is observed, accompanied by an absorption enhancement factor greater than one |
million. Nanoantenna enhanced THz spectroscopy (NETS) can find immediate applications in THz spectroscopic studies of nanocrystals and molecules at extremely low concentrations, and show a practicable route toward the characterization of individual nano-objects at these frequencies
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Ultima modifica il Sabato, 19 Dicembre 2015 10:14
