Fig. 2: Results of TF-μSR experiments.

a and c TF-μSR spectra collected above and below T_c for CsV₃Sb₅ with B_ext∣∣c and B_ext∣∣ab, respectively. The fast damping of the signal in the superconducting state reflects the inhomogeneous field distribution sensed by the muon ensemble as a result of vortex formation. Solid lines through the data points are fits using Eq. (5) in the Suppl. Inset: Scheme of the setup for μSR experiments on a single crystalline CsV₃Sb₅ sample. b and d show the Fourier spectra obtained by fast Fourier transformation of the spectra in a and c, respectively. The inset shows the spatial field variation within a flux line lattice of an anisotropic superconductor with an anisotropy parameter γ_λ ≃ 3, as explained in detail in Refs. ^72,75. The cutoff at low fields corresponds to the minimum in P(B) occurring at the midpoint of three adjacent vortices (\({B}_{\min }\)). The peak in P(B) arises from the saddle point midway between two adjacent vortices (B_saddle), whereas the long tail towards high fields is due to the region around the vortex cores (\({B}_{\max }\)). e Temperature variation of the square-root of the second moment of field distribution σ(T) [\(\sigma ={M}_{2}^{1/2}\)], as measured for the two applied field directions. The horizontal lines denote the relaxation due to nuclear magnetic moments along the two directions. f Internal magnetic field as a function of temperature in the superconducting state. A clear diamagnetic shift, an immanent feature of type-II superconductors, can be seen. g Temperature variation of the skewness parameter, \({\alpha }_{{{{\rm{sk}}}}}={M}_{3}^{1/3}/{M}_{2}^{1/2}\), for the B_ext∣∣c and B_ext∣∣ab set of experiments. The error bars represent the SD of the fit parameters.