======Seminário de Matéria Condensada - 05/03/2015, 11:00, Sala 201======


====Random gauge field contribution to the conductivity in graphene sheets with disordered ripples ====

===Rhonald Burgos - IF-UFF===


We study the effect of disordered ripples on the conductivity of monolayer graphene flakes[1]. We calculate the relaxation times and the Boltzmann conductivities associated with two mechanisms. First, we study the conductivity correction due to an external in-plane magnetic field //B//<sub>||</sub>. Due to the irregular local curvature found at graphene sheets deposited over a substrate, //B//<sub>||</sub> can be mapped into an effective random magnetic field perpendicular to the graphene surface. Second, we study the electron momentum relaxation due to intrinsic pseudo magnetic fields originated
from deformations and strain. We find that the competition between these mechanisms gives rise to a strong anisotropy in the 
conductivity tensor. This result provides a new strategy to quantitatively infer the strength of pseudo-magnetic fields in rippled graphene flakes.

[1] R. Burgos, //et al.//, Phys. Rev. B **91**, 115403 (2015).