Takuya Iwasaki

We study quantum transport properties in hexagonal boron nitride (hBN)/bilayer graphene (BLG) moiré superlattices in which their crystal axes are precisely aligned at a certain angle. Due to the moiré effect, the hBN/BLG moiré superlattices exhibit an energy gap at the charge neutrality point (CNP) even in the absence of a perpendicular electric field [ 1 ]. The hBN/BLG moiré superlattice is associated with non-trivial energy-band topology and a narrow energy band featuring a van Hove singularity. By employing a dual-gated device structure where both the perpendicular displacement field and the carrier density are individually controllable (Fig.1), systematic engineering of the energy-band structure can be achieved. Our data demonstrate the universality and diversity in the physics of hBN/BLG moiré superlattices [ 2 ].