Fig. 1: Basic characterization of the single-crystal EuSn2As2.
From: A candidate material EuSn2As2-based terahertz direct detection and imaging
a Crystalline structures of EuSn2As2, in which the atoms are arranged in puckered honeycomb layers bounded together by van der Waals’ forces, and an optical image at the corner with the grid length of 1 mm. b X-ray diffraction spectrum of the EuSn2As2 flakes with the corresponding Miller indices in parentheses. c Infrared reflection spectra at different sampling points. d The THz frequency-domain transmission spectra of with/without the samples. e Schematic illustration of the broadband absorption mechanisms between the bulk state and the gapless metallic state; and the blue and orange arrows indicate the low- and high-energy photons excitations, and the red solid circle indicates an electron with a spin, respectively. f The AFM image of EuSn2As2 flakes for device patterning indicates the thickness of the sample, and the scale bars are 4 μm (upper) and 2 μm (lower).
