Fig. 5. Angular dependence of the quantum oscillation frequency in the insulating state of YbB₁₂.

a Landau level indices (ν) as a function of the inverse field in the insulating state for the magnetic field applied along different angles with respect to [100]. Landau levels were indexed by tracking maxima and minima of the oscillations and are reported relative to the first observed oscillation. The indices follow the reverse quantum limit convention, i.e., lower Landau levels occur at lower fields. Linear fits to the data (solid lines) show nearly identical slopes. b Quantum oscillation frequencies from Landau level (LL) indexing and Fourier transforms (FFT) of the second derivatives of magnetoresistance (see Supplementary Note 5 for details) show minimal variation with angle. All measurements were at ≈650 mK. Error bars correspond to the 95% confidence bounds in the linear fit.