Graphene, an atomically thin monolayer of carbon atoms, due to its Dirac-like linear electronic dispersion, shows amazing electronic and optical properties, among which a striking non-linear response to electromagnetic fields, governing the optical and low-frequency transport features.
So far, the state-of-art understanding of these effects has been based on a picture of quasi non-interacting electrons.
In a couple of joint papers [1], [2], E. Cappelluti (ISM, CNR), and H. Rostami (Nordita, Sweden) provide the ground for a deeper understanding to desscribe in a moe compelling way the effects of the many-body scattering, with a specific focus about impurity scattering.
The present work paves the way for the control and a future engineering of the non-linear transport properties and of the third-harmonic generation response in the low-frequency regime of terahertz.

[1] H. Rostami and E. Cappelluti, Many-body effects in third harmonic generation of graphene Phys. Rev. B 103, 125415 (2021)

[2] H. Rostami and E. Cappelluti, Dominant role of two-photon vertex in nonlinear response in two-dimensional Dirac systems, npj 2D Mater Appl 5, 50 (2021)