  Using full-potential density functional theory (DFT) calculations, we found a
small asymmetry in the Fermi velocity of electrons and holes in graphene. These
Fermi velocity values and their average were found to decrease with increasing
in-plane homogeneous biaxial strain; the variation in Fermi velocity is
quadratic in strain. The results, which can be verified by Landau level
spectroscopy and quantum capacitance measurements of bi-axially strained
graphene, promise potential applications in graphene based straintronics and
flexible electronics.
