Piezoresistance in ballistic graphene

Abstract

We investigate the longitudinal and transverse piezoresistance effect in suspended graphene in the ballistic regime. Utilizing parametrized tight-binding Hamiltonian along with Landauer quantum transport formalism, we devise a methodology to evaluate the piezoresistance effect in graphene. We evaluate the longitudinal and transverse gauge factor of graphene along armchair and zigzag directions in the linear elastic limit (0%–10%). The gauge factors along armchair and zigzag directions are identical. Our model predicts a significant enhancement (≈1000%) in the value of transverse gauge factor compared to longitudinal gauge factor along with sign inversion. The calculated value of longitudinal gauge factor is ≈0.3, whereas the transverse gauge factor is ≈−3.3. We rationalize our prediction based on the deformation of Dirac cone and change in separation between transverse modes due to longitudinal and transverse strain. The results obtained herein can serve as a template for high-strain piezoresistance effect of graphene in nanoelectromechanical systems.