Network model for periodically strained graphene

The long-wavelength physics of monolayer graphene in the presence of periodic strain fields has a natural chiral scattering network description. When the strain field varies slowly compared to the graphene lattice and the effective magnetic length of the induced valley pseudomagnetic field, the low-energy physics can be understood in terms of valley-polarized percolating domain-wall modes. Inspired by a recent experiment, we consider a strain field with threefold rotation and mirror symmetries but without twofold rotation symmetry, resulting in a system with the connectivity of the oriented kagome network. Scattering processes in this network are captured by a symmetry-constrained phenomenological S matrix. We analyze the phase diagram of the kagome network and show that the bulk physics of the strained graphene can be qualitatively captured by the network when we account for a percolation transition at charge neutrality. We also discuss the limitations of this approach to properly account for boundary physics.

Automated summary

The long-wavelength physics of monolayer graphene in the presence of periodic strain fields can be described using a chiral scattering network. A strain field with threefold rotation and mirror symmetries, but without twofold rotation symmetry, results in the connectivity of the oriented kagome network. Scattering processes in this network are captured by a symmetry-constrained phenomenological S matrix. The bulk physics of strained graphene can be qualitatively accounted for by this network, but it has limitations in properly accounting for the boundary physics.