Fig. 1: ⁵¹V-NMR evidence for the CDW order.

a The crystal structure of CsV₃Sb₅ at room temperature. b Temperature dependence of the ⁵¹V-NMR spectra above T_CDW(black color) and below T_CDW (red color) with the external magnetic field applied along the c-axis. The low- and high-frequency central peaks of 90.3 K were assigned as l₁ and l₂, respectively. The sharp peak around 135.7 MHz is from the Cu coil. c Contour plot of the ⁵¹V central lines around T_CDW, there are three peaks between 98 K and 92 K. d Temperature dependence of the Knight shift K_c for ⁵¹V central line. The average K_c of the two peaks is plotted by black circles. e Temperature dependence of the Knight shift difference ΔK between the two split peaks. f Temperature-dependent 1/T₁T for ⁵¹V measured at the central lines. Below T_CDW, 1/T₁T and K_c of l₁ and l₂ are plotted by red dots and blue triangles, respectively. The dash lines are the guides to the eyes. The error bar of 1/T₁T is the s. d. in fitting the recovery curve.