Details

Autor(en) / Beteiligte

• Eisele, M.
• Cocker, T. L.
• Huber, M. A.
• Plankl, M.
• Viti, L.
• Ercolani, D.
• Sorba, L.
• Vitiello, M. S.
• Huber, R.

Titel

Ultrafast multi-terahertz nano-spectroscopy with sub-cycle temporal resolution

Ist Teil von

• Nature photonics, 2014-11, Vol.8 (11), p.841-845

Ort / Verlag

London: Nature Publishing Group

Erscheinungsjahr

2014

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Phase-locked ultrashort pulses in the rich terahertz spectral range have provided key insights into phenomena as diverse as quantum confinement, first-order phase transitions, high-temperature superconductivity and carrier transport in nanomaterials. Ultrabroadband electro-optic sampling of few-cycle field transients can even reveal novel dynamics that occur faster than a single oscillation cycle of light. However, conventional terahertz spectroscopy is intrinsically restricted to ensemble measurements by the diffraction limit. As a result, it measures dielectric functions averaged over the size, structure, orientation and density of nanoparticles, nanocrystals or nanodomains. Here, we extend ultrabroadband time-resolved terahertz spectroscopy to the sub-nanoparticle scale (10 nm) by combining sub-cycle, field-resolved detection (10 fs) with scattering-type near-field scanning optical microscopy (s-NSOM). We trace the time-dependent dielectric function at the surface of a single photoexcited InAs nanowire in all three spatial dimensions and reveal the ultrafast (<50 fs) formation of a local carrier depletion layer.