Fig. 5
From: Direct observation of valley-polarized topological edge states in designer surface plasmon crystals
Near-field maps of valley-polarized edge states and corresponding spatial Fourier spectra. a, b Simulated field maps of E z component at 7.50 GHz on the xy plane 1 mm above the metallic surface. The source denoted by the blue star is placed at terminal 1 in a and terminal 2 in b. Gray arrows denote the direction of the valley-polarized edge states. Green dashed rectangles denote the regions of the area 205 × 220 mm2 scanned in experiments. The scale bar is 60 mm. c, d Measured field maps of E z component at 7.50 GHz in the region of the sample denoted by green dashed rectangles in a and b, respectively. The blue dashed rectangles denote the interior regions where we perform Fourier transforms. The scale bar is 40 mm. e, f Spatial Fourier spectra of the scanned E z component. The green solid hexagons represent the FBZs and the yellow dashed circles represent the 7.50-GHz isofrequency contours of the light cone. The color indicates the amplitude of E z component in field maps and the amplitude of spatial Fourier transforms in spatial Fourier spectra, respectively
