Twisted Nano-optics: Manipulating Light at the Nanoscale with Twisted Phonon Polaritonic Slabs.
Abstrak
Recent discoveries have shown that when two layers of van der Waals (vdW) materials are superimposed with a relative twist angle between their respective in-plane principal axes, the electronic properties of the coupled system can be dramatically altered. Here, we demonstrate that a similar concept can be extended to the optics realm, particularly to propagating phonon polaritons - hybrid light-matter interactions -. To do this, we fabricate stacks composed of two twisted slabs of a polar vdW crystal (α-MoO3) supporting low-loss anisotropic phonon polaritons (PhPs), and image the propagation of the latter when launched by localized sources (metal antennas). Our images reveal that under a critical angle the PhPs isofrequency curve (determining the PhPs momentum at a fixed frequency) undergoes a topological transition. Remarkably, at this angle, the propagation of PhPs is strongly guided along predetermined directions (canalization regime) with no geometrical spreading (diffraction-less). These results demonstrate a new degree of freedom (twist angle) for controlling the propagation of polaritons at the nanoscale with potential for nano-imaging, (bio)-sensing, quantum applications and heat management.
Penulis (8)
J. Duan
N. Capote-Robayna
J. Taboada-Gutiérrez
G. Álvarez‐Pérez
I. Prieto
J. Martín-Sánchez
A. Nikitin
P. Alonso‐González
Akses Cepat
- Tahun Terbit
- 2020
- Bahasa
- en
- Total Sitasi
- 187×
- Sumber Database
- Semantic Scholar
- DOI
- 10.1021/acs.nanolett.0c01673
- Akses
- Open Access ✓