Anisotropic Electronic Transport in Strain Superlattices in Graphene

Strain superlattice effects in atomically thin materials such as graphene can lead to novel quantum phenomena and also have applications in the field of bendable electronics. In this research, we generate tensile strain in monolayer graphene by stacking it on a self-assembled array of dielectric nanospheres (NS), thus creating a strain superlattice (SL). Previous [1] two terminal charge transport measurements on these graphene SLs revealed strain-tunable conductance dips associated with SL miniband effects. We now report studies of the Hall effect and non-local transport in these graphene-NS systems. We observe anisotropic transport characteristics and symmetry breaking which may be attributed to the lifting of the valley degeneracy in these systems.

[1] Y. Zhang et al, npj 2D Materials and Applications 2, 31 (2018)