Epitaxial growth of trilayer Graphene Moiré superlattice

The graphene-based moiré superlattice has been demonstrated as an exciting system for investigating strong correlation phenomenon[1-15]. However, the fabrication of such moiré superlattice mainly relies on transfer technology. Here, we report the epitaxial growth of trilayer graphene (TLG) moiré superlattice on hexagonal boron nitride (hBN) by a remote plasma enhanced chemical vapor deposition method. The as grown TLG/hBN shows a uniform moiré pattern with a period of ~15nm by atomic force microscopy (AFM) imaging, which agrees with the lattice mismatch between graphene and hBN[16, 17]. By fabricating the device with both top and bottom gates, we observe a gate-tunable bandgap at charge neutral point (CNP) and displacement field tunable satellite resistance peaks at half and full fillings. The resistance peak at half-filling indicates a strong electron-electron correlation in our grown TLG/hBN superlattice. In addition, we observe quantum Hall states at Landau level filling factors ν = 6, 10, 14…, indicating that our grown trilayer graphene has the ABC stacking order. Our work suggests that epitaxy provides an easy way to fabricate stable and reproducible two-dimensional strongly correlated electronic materials.