Effect of strain on the excitonic polarization in graphene ribbons.

We study the coherent polarization of excitons in strained graphene ribbons using a bosonization scheme. Within linear elastic theory and a tight-binding approach, we observe that strain can generate a marked influence on the coherent polarization of excitons and even effectively enhance polarization of excitons on certain conditions. We find that the polarization direction of the positive-wavevector excitons is opposite to that of the negative-wavevector excitons under high strain. We explain the micromechanism of generating these phenomena. [ABSTRACT FROM AUTHOR]