Fig. 4: Magnetic field dependence of thermoelectric voltage.
From: Thermopower probes of emergent local moments in magic-angle twisted bilayer graphene
a, Top: VTh with ν for different B∥ at 25 K. Here the VTh is normalized to VTh measured at B∥ = 0T. Bottom: the reduction of VTh can be observed with increasing B∥, and the effect is more pronounced for the valence band and plotted at ν = −3.2 (vertical black arrow), which shows 30% reduction. b, Top: the evolution of normalized VTh with B⊥ at 20 K. Bottom: in contrast to B∥, a larger decrease of the VTh signal is observed with increasing B⊥ and plotted for ν = −3.55 (vertical black arrow), where 50% reduction can be seen. c, Normalized entropy estimated from the integral of the VTh with ν at 20 K from B⊥ data. The peak position of the entropy saturates to ν ≈ ±1.3 (vertical dashed black lines) with higher B⊥. d, Theoretical entropy calculated using atomic limit for zero magnetic field. The shape of the experimental entropy in c resembles the theoretical entropy of local moments.
