Strain tunable magnetotransport study of ABC trilayer graphene/h-BN moiré superlattices

The number of atomic layers changes the electronic band structure of graphene dramatically. While monolayer graphene hosts linear bands with massless fermions, trilayer ABC-stacked graphene exhibits a very flat quartic band at the K point and is a particularly suitable platform for strongly correlated physics. When ABC trilayer graphene is aligned with the h-BN layer, the addition of the moiré superlattice can create narrow minibands, and low energy bands can become flat and isolated near charge neutrality. Mott insulating states and unconventional superconductivity have been observed in ABC-TLG/h-BN heterostructures. Perpendicular electric field and strain are important ways to tune these bands. In our work, we have fabricated ABC-TLG/h-BN aligned heterostructures with dual graphite gates, on flexible substrates to apply both perpendicular electric field and intralayer strain onto the device. We study the responses of low energy bands by performing magnetotransport measurements at low temperatures.