High-Magnetic-Field Tunneling Spectra of A B C -Stacked Trilayer Graphene on Graphite

A B C -stacked trilayer graphene (TLG) was predicted to exhibit novel many-body phenomena due to the existence of almost dispersionless flat bands near the charge neutrality point. Here, using high-magnetic-field scanning tunneling microscopy, we present Landau Level (LL) spectroscopy measurements of high-quality A B C -stacked TLG on graphite. We observe an approximately linear magnetic-field scaling of valley splitting and spin splitting in the A B C -stacked TLG. Our experiment indicates that the spin splitting decreases dramatically with increasing the LL index. When the lowest LL is partially filled, we find an obvious enhancement of the spin splitting, attributing to strong many-body effects. Moreover, we observe linear energy scaling of the inverse lifetime of quasiparticles, providing an additional evidence for the strong electron-electron interactions in the A B C -stacked TLG. These results imply that interesting broken-symmetry states and novel electron correlated effects could emerge in the A B C -stacked TLG in the presence of high magnetic fields.