Fig. 3: Hyperbolic plasmons along the armchair and zigzag direction.
From: Manipulating hyperbolic transient plasmons in a layered semiconductor
a Near-field amplitude images of polariton propagating along the armchair and the zigzag direction. The BP thickness is 700 nm, the scale bar is 1 μm, and the black arrow indicates the incident probing beam direction. b, c Plasmon wavelengths of the BP slabs with different thicknesses. d Schematic of the air/5-nm-thick PxOy/high-doping BP/pristine BP/Si five-layer stacking structure. The double arrow marked d is the thickness of the BP. e, f Cross-sectional of the real part of z component electric field Re(Ez) at v/c = 950 cm–1 of the plasmon mode propagating along the armchair (e) and the zigzag (f) direction with the BP thickness d = 200 nm and 800 nm, respectively. g, h Low-loss plasmon propagating along the armchair (g) and the zigzag (h) direction. The symbols are experimental data. The solid lines are the fitting result of Eq. (4).
