Extended Data Fig. 2: Isospin degeneracy inferred from Landau level spacing.
From: Orbital multiferroicity in pentalayer rhombohedral graphene
Color plots of four-probe resistance Rxx as a function of carrier density n and displacement field E for the small hole doping VPHM region (a) and large hole doping UP region (b) measured at B = 2 T and a temperature of 300 mK. The straight features correspond to Landau levels and the spacing indicates the degeneracy d of the band. With d = 4, all four isospin flavors are present at the Fermi surfaces. With d = 2, two out of four isospin flavors have Fermi surfaces (the so-called half-metal).
