Fig. 3: Muon spin relaxation data of KCu₆AlBiO₄(SO₄)₅Cl.

a LF-μSR spectra (obtained in a dilution refrigerator) at representative temperatures (see Supplementary Note 3 for the spectra obtained using the ⁴He cryostat). The thick lines behind the data points are the fitted curves (see text for details). b The LF-μSR spectrum measured at 58 mK. The spectrum decreases continuously without oscillations up to 15 μs. c μSR spectra measured at 58 mK under several longitudinal magnetic fields. d Projection along the c axis. e Projection along the a axis. The muon site was obtained by a Hartree potential calculation. f Temperature dependence of the muon spin relaxation rate λ. The grey solid lines are guides for the eyes. g Magnetic-field dependences of the muon spin relaxation rate λ. The solid curves are fitted to a power law of the form 1/(a + bH^α). The error bars in a, b and c represent 1 s.d. and in f and g the maximum possible variation due to correlation of parameters.