Fermi Velocity Modulation in Graphene by Strain Engineering

TL;DR

This study uses density functional theory to show that applying in-plane biaxial strain to graphene decreases its Fermi velocity quadratically, with potential applications in strain-based electronics.

Contribution

It provides the first detailed theoretical analysis of how biaxial strain affects Fermi velocity in graphene, highlighting a quadratic relationship.

Findings

Fermi velocity decreases with increasing biaxial strain

The variation in Fermi velocity is quadratic in strain

Results can be verified by spectroscopy and capacitance measurements

Abstract

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.