Study of Strain-Induced Modulation of Electronic Properties of Monolayer Graphene Using Gauge Field Approach

The alteration of the lattice structure of monolayer graphene under strain and the resulting modulation of the band structure and the electronic properties are studied here in a view to figure out the electromechanical responses. The tight binding model (TBM) aided by effective-mass approximation (EMA) has effectively been used to study the impact of anisotropic strain. In this approach, the components of anisotropic strain tensor being connected to the amplitudes of electron hopping energy should alter the gauge field. The Dirac Hamiltonian is modified accordingly with the introduction of the gauge field term in it and is used to determine the evolution of strain-dependent dispersion energy. It is observed that under EMA, only 25% of anisotropic strain is sufficient to open up large band gap of ~ 3.5 eV when the strain is along zigzag direction, while it is 1.5 eV when the strain is along armchair direction. Therefore, by varying strain, it is possible to tune band gap, vis-a-vis electronic properties. The strain induced electron effective mass (EEM), density of states (DOS), carrier concentration, and intrinsic conductivity has been determined for the complete evaluation of the electronic properties of graphene sheet.