Nanoscale Imaging with 2D materials

Datum

27.10.2015

Zeit

16:40 - 18:10

Sprecher

Prof. Dr. Thomas Taubner, Institute of Physics (IA), RWTH Aachen University

Serie

TUD Physikalisches Kolloquium

Sprache

en

Hauptthema

Physik

Andere Themen

Physik

Host

Prof. Dr. Sebastian Diehl, Fachrichtung Physik

Beschreibung

Near-field superlenses [1] have the ability to break the diffraction limit due to the resonance of surface plasmon (or phonon) polaritons (SPPs) and enable applications like optical lithography and near-field imaging. Combining a superlens with scattering-type-near-field optical microscopy (s-SNOM) enabled subsurface imaging of metallic nanostructures [2].Up to now, the practical application of a superlens has been limited by its narrow bandwidth and complicated fabrication. I will show our latest results on two new “superlensing” concepts using natural layered 2D-materials that overcome these limitations, Graphene and hexagonal boron nitride (hBN): Graphene is a one-atom-thick planar sheet supporting surface plasmons at frequencies in the infrared (IR) and terahertz (THz) spectral range. In contrast to conventional superlenses, the nonresonant operation of our so-called “Graphene-Lens” (GL) [3] provides the advantages of a broad intrinsic bandwidth, a low sensitivity to losses and the possibility for continuously frequency-tunable imaging while maintaining a good subwavelength resolution of better than λ/10. I will present first experimental evidence for graphene superlensing [4] and our latest subwavelength imaging results using thin layers of hBN, a material that supports surface phonon polaritons and exhibits exciting new subwavelength imaging properties due to its hyperbolic dispersion [5].

1.    J.B. Pendry, Physical Review Letters 85, 3966 (2000).

2.    T. Taubner, et al. Science 313, 1595 (2006).

3.    P. Li and T. Taubner, ACS Nano6, 10107 (2012).

4.    P. Li et al., Nano Letters,14, 4400-4405 (2014).

5.    P. Li et al, Nature Communications, 6,7507 (2015).

 

Links

• http://tu-dresden.de/veranstaltungen/termin?id=TUD5615023e71a30

Letztmalig verändert: 27.10.2015, 08:44:14