Actively Tunable Phonon Polaritons in Twisted α-MoO3 Slabs With Weyl Semimetal Interlayer

Hybrid phonon polaritons (PhPs) in polar van der Waals (vdW) layered materials are very appealing for the confinement of light at the nanoscale and have facilitated various applications. However, manipulation of in-plane anisotropic PhPs via external stimuli presents a significant challenge. Here, we offer a lithography-free avenue to create structure for the realization of hybridized PhPs from
$\alpha $
-phase molybdenum trioxide
(3)
vdW crystal with dependence on the chemical potential of Weyl semimetals (WSM). We demonstrate the distinct dispersion tunability of the strongly coupled PhPs and the optical topologic transitions from open to closed iso-frequency contours (IFCs). As the chemical potential is strongly temperature dependent, an alteration of the hybridization will be met by changing the temperature of surroundings, which enables an efficient way for the control of light-matter interaction at nanoscale in the mid-infrared (MIR) range.