4736982
doi
10.1021/acsphotonics.8b00636
oai:zenodo.org:4736982
user-eu
Govyadinov,Alexander A.
CIC Nanogune
Maissen,Curdin
CIC Nanogune
Chuvilin, Andrey
CIC Nanogune; Ikerbasque
Berger,Andreas
CIC Nanogune
Hillenbrand, Rainer
IKERBASQUE, CIC nanoGUNE and UPV/EHU,
Understanding the Image Contrast of Material Boundaries in IR Nanoscopy Reaching 5 nm Spatial Resolution
Mastel, Stefan
CIC Nanogune
info:eu-repo/semantics/openAccess
Creative Commons Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/legalcode
scattering-type scanning near-field optical microscopy (s-SNOM) IR and THz nanoscopy focused ion beam (FIB) machining
<p>Scattering-type scanning near-field optical microscopy (s-SNOM) allows for nanoscale-resolved Infrared (IR) and Terahertz (THz) imaging, and thus has manifold applications ranging from materials to biosciences. However, a quantitatively accurate understanding of image contrast formation at materials boundaries, and thus spatial resolution is a surprisingly unexplored terrain. Here we introduce the read/write head of a commercial hard disk drive (HDD) as a most suitable test sample for fundamental studies, given its well-defined sharp material boundaries perpendicular to its ultrasmooth surface. We obtain unprecedented and unexpected insights into the s-SNOM image formation process, free of topography-induced contrasts that often mask and artificially modify the pure near-field optical contrast. Across metal-dielectric boundaries, we observe non-point-symmetric line profiles for both IR and THz illumination, which are fully corroborated by numerical simulations. We explain our findings by a sample-dependent confinement and screening of the near fields at the tip apex, which will be of crucial importance for an accurate understanding and proper interpretation of high-resolution s-SNOM images of nanocomposite materials. We also demonstrate that with ultrasharp tungsten tips the apparent width (resolution) of sharp material boundaries can be reduced to about 5 nm.</p>
This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Photonics, copyright © American Chemical Society after peer review and technical editing by the publisher.
Zenodo
2018-07-11
info:eu-repo/semantics/article
4736981
user-eu
award_title=Plasmon Enhanced Terahertz Electron Paramagnetic Resonance; award_number=767227; award_identifiers_scheme=url; award_identifiers_identifier=https://cordis.europa.eu/projects/767227; funder_id=00k4n6c32; funder_name=European Commission;
1620136097.161757
788387
md5:aebcdb2369fa884e53c0d7420a73e242
https://zenodo.org/records/4736982/files/Supporting information.pdf
520507
md5:7aae5cd3bb6385dc528ed707fd7ae48b
https://zenodo.org/records/4736982/files/Understanding the image contrast .pdf
public