Graphene phonon softening and splitting by directional straining
Yang, X. X.
Li, J. W.
Liao, W. H.
Liu, Y. H.
Sun, Chang Qing
Date of Issue2015
School of Electrical and Electronic Engineering
Strain-induced graphenephonon softening and phonon band splitting are indeed fascinating, which were attributed to the phonon double resonant scattering without intrinsic involvement of C-C bond relaxation. Here, we show that the lengthening and weakening of the C-C bond softens the phonon and that the mismatching between the uniaxial strain and the C3vbond geometry splits the band. In addition to the force constant of 11.8 N/m for a C-C bond in graphene, consistency between theory and measurements derives that if the strain is along a bond, maximal band splitting happens; if the strain is perpendicular, no band splitting occurs.
Applied Physics Letters
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