TY - JOUR
T1 - Nonlinear optical response of doped monolayer and bilayer graphene
T2 - Length gauge tight-binding model
AU - Hipólito, Fábio
AU - Taghizadeh, Alireza
AU - Pedersen, Thomas Garm
PY - 2018
Y1 - 2018
N2 - We compute the nonlinear optical response of doped monolayer and bilayer graphene using the full dispersion based on tight-binding models. The response is derived with the density matrix formalism using the length gauge and is valid for any periodic system, with arbitrary doping. By collecting terms that define effective nonlinear response tensors, we identify all nonlinear Drude-like terms (up to third order) and show that all additional spurious divergences present in the induced current vanish. The nonlinear response of graphene comprises a large Drude-like divergence and three resonances that are tightly connected with transitions occurring in the vicinity of the Fermi level. The analytic solution derived using the Dirac approximation captures accurately the first- and third-order responses in graphene, even at very high doping levels. The quadratic response of gapped graphene is also strongly enhanced by doping, even for systems with small gaps such as commensurate structures of graphene on SiC. The nonlinear response of bilayer graphene is significantly richer, combining the resonances that stem from doping with its intrinsic strong low-energy resonances.
AB - We compute the nonlinear optical response of doped monolayer and bilayer graphene using the full dispersion based on tight-binding models. The response is derived with the density matrix formalism using the length gauge and is valid for any periodic system, with arbitrary doping. By collecting terms that define effective nonlinear response tensors, we identify all nonlinear Drude-like terms (up to third order) and show that all additional spurious divergences present in the induced current vanish. The nonlinear response of graphene comprises a large Drude-like divergence and three resonances that are tightly connected with transitions occurring in the vicinity of the Fermi level. The analytic solution derived using the Dirac approximation captures accurately the first- and third-order responses in graphene, even at very high doping levels. The quadratic response of gapped graphene is also strongly enhanced by doping, even for systems with small gaps such as commensurate structures of graphene on SiC. The nonlinear response of bilayer graphene is significantly richer, combining the resonances that stem from doping with its intrinsic strong low-energy resonances.
UR - http://www.scopus.com/inward/record.url?scp=85057891292&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.98.205420
DO - 10.1103/PhysRevB.98.205420
M3 - Journal article
SN - 2469-9950
VL - 98
JO - Physical Review B
JF - Physical Review B
IS - 20
M1 - 205420
ER -