Fig. 5: Splitting of vHs under perpendicular magnetic fields.
From: Spectroscopy of a tunable moiré system with a correlated and topological flat band
a STS measurements between −nS and nS under a perpendicular magnetic field of 4 T, taken with Vset = −400 mV, Iset = 800 pA and Vmod = 0.5 mV. b Tunneling spectra at half filling of the C1 band under various perpendicular magnetic fields. Traces are offset for clarity. c Splitting of the C1 vHs as a function of perpendicular magnetic field B at half filling (blue symbols) and three-quarter filling (red symbols), obtained from Gaussian fitting of the split peaks. The error bars represent 95% confidence bounds of the fit. The dashed lines are the linear fit of the splitting, corresponding to \(\triangle E=2g{\mu }_{B}B\) with g-factor noted in the legend. d schematic of C1 band’s response to magnetic fields. The two valleys (red and blue) shift in opposite energy directions due to their opposite valley Chern numbers. e illustration of valley splitting estimation based on Chern number of the band. On K1 (K2) valley, the CNP gap between V1 and C1 carries Chern number C = 2 (C = −2), which move to the top of C1 band (bottom of V1 band) at half flux per moiré unit cell. The red and blue dashed lines represent the vHs of C1 band in the two valleys, and wc and wv. denote the bandwidth of C1 and V1 band at zero field.
