Filters

2020 - 20212

More filters

2021 - 20222
Reset filters

Settings

Author: Lienau, Christoph × Type: Article ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Femtosecond Field‐Driven On‐Chip Unidirectional Electronic Currents in Nonadiabatic Tunneling Regime
    (Weinheim : Wiley VCH, 2021) Shi, Liping; Babushkin, Ihar; Husakou, Anton; Melchert, Oliver; Frank, Bettina; Yi, Juemin; Wetzel, Gustav; Demircan, Ayhan; Lienau, Christoph; Giessen, Harald; Ivanov, Misha; Morgner, Uwe; Kovacev, Milutin
    Recently, asymmetric plasmonic nanojunctions have shown promise as on-chip electronic devices to convert femtosecond optical pulses to current bursts, with a bandwidth of multi-terahertz scale, although yet at low temperatures and pressures. Such nanoscale devices are of great interest for novel ultrafast electronics and opto-electronic applications. Here, the device is operated in air and at room temperature, revealing the mechanisms of photoemission from plasmonic nanojunctions, and the fundamental limitations on the speed of optical-to-electronic conversion. Inter-cycle interference of coherent electronic wavepackets results in a complex energy electron distribution and birth of multiphoton effects. This energy structure, as well as reshaping of the wavepackets during their propagation from one tip to the other, determine the ultrafast dynamics of the current. It is shown that, up to some level of approximation, the electron flight time is well-determined by the mean ponderomotive velocity in the driving field.
  • Thumbnail Image
    Item
    Strongly coupled, high-quality plasmonic dimer antennas fabricated using a sketch-and-peel technique
    (Berlin : de Gruyter, 2020) Gittinger, Moritz; Höflich, Katja; Smirnov, Vladimir; Kollmann, Heiko; Lienau, Christoph; Silies, Martin
    A combination of helium- and gallium-ion beam milling together with a fast and reliable sketch-and-peel technique is used to fabricate gold nanorod dimer antennas with an excellent quality factor and with gap distances of less than 6 nm. The high fabrication quality of the sketch-and-peel technique compared to a conventional ion beam milling technique is proven by polarisation-resolved linear dark-field spectromicroscopy of isolated dimer antennas. We demonstrate a strong coupling of the two antenna arms for both fabrication techniques, with a quality factor of more than 14, close to the theoretical limit, for the sketch-and-peel-produced antennas compared to only 6 for the conventional fabrication process. The obtained results on the strong coupling of the plasmonic dimer antennas are supported by finite-difference time-domain simulations of the light-dimer antenna interaction. The presented fabrication technique enables the rapid fabrication of large-scale plasmonic or dielectric nanostructures arrays and metasurfaces with single-digit nanometer scale milling accuracy. © 2020 Christoph Lienau, Martin Silies et al., published by De Gruyter, Berlin/Boston.