Extended Data Fig. 2: Quantum Hall states at low magnetic fields.

a-c, fan diagrams of the conductance derivative with respect to the charge carrier density of device A2 (cf. Supporting Table 1) at E = 0 mV nm⁻¹ in a, E = 24 mV nm⁻¹ in b and E = 47 mV nm⁻¹ in c. The filling factors and their corresponding slopes are indicated on the top of each panel. The roman numerals indicate the associated spontaneous quantum Hall states, namely the LAF/CAF state (I), the ALL state (III) and the QAH state (IV). d-f, Fan diagrams of the conductance derivative with respect to the charge carrier density of device B1 (cf. Supporting Table 1) at E = 0 mV nm⁻¹ in d, E = −20 mV nm⁻¹ in e and E = −60 mV nm⁻¹ in f. The filling factors and their corresponding slopes are indicated on the top of each panel.