Ultrafast single-nanowire multi-terahertz spectroscopy with sub-cycle temporal resolution
Abstract
Phase-locked ultrashort pulses in the rich terahertz (THz) 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 THz 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 THz spectroscopy (20 - 50 THz) 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.
Cite
@article{arxiv.1604.04304,
title = {Ultrafast single-nanowire multi-terahertz spectroscopy with sub-cycle temporal resolution},
author = {M. Eisele and T. L. Cocker and M. A. Huber and M. Plankl and L. Viti and D. Ercolani and L. Sorba and M. S. Vitiello and R. Huber},
journal= {arXiv preprint arXiv:1604.04304},
year = {2016}
}