Fig. 5: PhPs dispersion and lifetimes in thin LiV₂O₅ layers.

a Experimental (red dots) PhP dispersion extracted by s-SNOM imaging along the a direction of the LiV₂O₅ layer (213 nm) measured in Fig. 4. Experimental points are shown with error bars that take into account the experimental and fitting errors. Theoretically calculated dispersion (using transfer matrix (TM) formalism) is shown as a color plot. A good agreement with the experiment is obtained. The white horizontal solid lines indicate \({\omega }_{{TO}}\) and \({\omega }_{{LO}}\) defining RB_a2, where canalized PhPs are excited. b Same as a for the b direction in LiV₂O₅. A good agreement with the experiment is obtained. The white dashed line indicates the frequency of canalization of PhPs. c, d s-SNOM line traces along the b and a directions (Fig. 5c, d, respectively) of the images shown in Fig. 4f, g at the canalization frequency \(\omega=\) 1007 cm⁻¹ on LiV₂O₅ thin layers with thicknesses 213 nm and 116 nm. Fitting curves of the line traces along the b direction using a damped sine wave function are shown as red solid lines to extract the lifetimes (τ).