Fig. 4: Hyperbolic rays in the Kagome metal CsV3Sb5.
a AFM and b–d Near-field amplitude images of a 407-nm-thick crystal. A pre-patterned gold launcher underlying the crystal can be clearly visualized through near-field imaging. The scale bar is 2 μm in length. e The profile of the near-field amplitude extracted along the dashed lines at the same locations in panels b–d. f The simulated electric field distribution emitted by a dipole launcher is plotted on a cross-section of the CsV3Sb5 flake. For better illustration, panel i) uses \({\epsilon }_{\perp }={{{{\mathrm{Re}}}}}\left[{\epsilon }_{{{{{{\rm{ab}}}}}}}\right]+\frac{i}{2}{{{{{\rm{Im}}}}}}\left[{\epsilon }_{{{{{{\rm{ab}}}}}}}\right]\) with \({\epsilon }_{{{{{{\rm{c}}}}}}}=-10\), while panel ii) uses the same \({\epsilon }_{\perp }\) but with \({\epsilon }_{{{{{{\rm{c}}}}}}}=10\).
