Heterostrain tuning of Moire superlattice in Bernal-stacked bilayer graphene*

Moire superlattices formed by twisting two-dimensional crystals attract great research interest in recent years, exhibiting novel quantum transport properties and strongly correlated behaviors. Since the electronic properties of two-dimensional materials are sensitive to the lattice structure and symmetry, mechanical strain stands out as a promising tuning knob for the Moire superlattices. A particularly interesting approach is to create "Moire without a twist" through the heterostrain, where different strains are applied to the two atomic layers in a bi-layer stack, resulting in different lattice constants and hence Moire superlattice. In this work we explore the potential formation of a strain-tunable Moire superlattice by applying such heterostrain strain on a hBN encapsulated bilayer graphene field effect device. We characterize the gate-dependent charge transport properties while changing the heterostrain at low temperatures and in strong magnetic fields, which allows us to infer the formation of a Moire superlattice which modifies the band structure of intrinsic Bernal-stacked bilayer graphene.