Generalized effective hamiltonian for graphene under non-uniform strain

TL;DR

This paper develops a systematic low-energy Hamiltonian for strained graphene, revealing a new gap-opening term related to pseudomagnetic fields and pseudospin, with couplings derived from a tight-binding model.

Contribution

It introduces a comprehensive derivative expansion of the effective Hamiltonian for non-uniformly strained graphene, including a novel Zeeman-like coupling term.

Findings

Identification of a new gap-opening term in the Hamiltonian.

Quantitative determination of coupling constants from a tight-binding model.

Enhanced understanding of strain effects on graphene's electronic properties.

Abstract

We use a symmetry approach to construct a systematic derivative expansion of the low energy effective Hamiltonian modifying the continuum Dirac description of graphene in the presence of non-uniform elastic deformations. We extract all experimentally relevant terms and describe their physical significance. Among them there is a new gap-opening term that describes the Zeeman coupling of the elastic pseudomagnetic field and the pseudospin. We determine the value of the couplings using a generalized tight binding model.