ACS Nano
ACS Nano
5 years ago

Mechanical Detection and Imaging of Hyperbolic Phonon Polaritons in Hexagonal Boron Nitride

Mechanical Detection and Imaging of Hyperbolic Phonon Polaritons in Hexagonal Boron Nitride
Siyuan Dai, Dimitri N. Basov, Michele Tamagnone, Luis A. Jauregui, Philip Kim, Michael M. Fogler, Kundan Chaudhary, William L. Wilson, Antonio Ambrosio, Federico Capasso
Mid-infrared nanoimaging and spectroscopy of two-dimensional (2D) materials have been limited so far to scattering-type scanning near-field optical microscopy (s-SNOM) experiments, where light from the sample is scattered by a metallic-coated atomic force microscope (AFM) tip interacting with the material at the nanoscale. These experiments have recently allowed imaging of plasmon polaritons in graphene as well as hyperbolic phonon polaritons in hexagonal boron nitride (hBN). Here we show that the high mechanical sensitivity of an AFM cantilever can be exploited for imaging hyperbolic phonon polaritons in hBN. In our imaging process, the lattice vibrations of hBN micrometer-sized flakes are locally enhanced by the launched phonon polaritons. These enhanced vibrations are coupled to the AFM tip in contact with the sample surface and recorded during scanning. Imaging resolution of Δ/20 is shown (Δ being the polaritonic fringes’ separation distance), comparable to the best resolution in s-SNOM. Importantly, this detection mechanism is free from light background, and it is in fact the first photonless detection of phonon polaritons.

Publisher URL: http://dx.doi.org/10.1021/acsnano.7b02323

DOI: 10.1021/acsnano.7b02323

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.