Strain tunable magnetotransport study of graphene/h-BN heterostructures

Graphene is a single atomic layer of carbon atoms in a hexagonal lattice, which has attracted plenty of research attention since its discovery. Graphene with different layers hosts unique varieties of electronic band structures. In the monolayer graphene, it hosts a relativistic Dirac spectrum with linear energy-momentum dispersion. The energy dispersion of ABA trilayer graphene is a combination of linear dispersion of monolayer graphene and quadratic dispersion of bilayer graphene. On the other hand, the energy dispersion of ABC trilayer graphene is a very flat cubic relation. When twist graphene and graphene or graphene and h-BN by a small angle, a long wave-length moiré superlattice results. New strongly correlated physics phenomena show up at specific angles. Besides the perpendicular electric field, strain is another way to modify the band structures. In our work, we have fabricated graphene/h-BN heterostructures with graphite gate on flexible substrates to apply both perpendicular electric field and intralayer strain onto the device. We study the preliminary responses of low energy bands by performing magnetotransport measurements at low temperatures.