Effect of Strain on Density of States and Directional Dependent Electron Effective Mass of Two Dimensional Intrinsic Graphene

A simple theoretical model is presented to study the density of states (DOS) and directional dependence of electron effective mass (DD-EEM) of graphene in presence of anisotropic strain field. A generalized expression of anisotropic dispersion relation in tight-binding approximation (TBA) is used to determine DOS and DD-EEM. It is found that both DOS and DD-EEM show nonlinear variation with induced strain and its direction of application. In graphene strain field is highly anisotropic and that infuses nonlinearity in dispersion energy. This is the key to the control of transport properties of graphene by inducing strain in it.