Currents and pseudomagnetic fields in strained graphene rings

Abstract

We study the effects of strain on the electronic properties and persistent current characteristics of a graphene ring using the Dirac representation. For a slightly deformed graphene ring flake, one obtains sizable pseudomagnetic (gauge) fields that may effectively reduce or enhance locally the applied magnetic flux through the ring. Flux-induced persistent currents in a flat ring have full rotational symmetry throughout the structure; in contrast, we show that currents in the presence of a circularly symmetric deformation are strongly inhomogeneous, due to the underlying symmetries of graphene. This result illustrates the inherent competition between the “real” magnetic field and the “pseudo” field arising from strains, and suggests an alternative way to probe the strength and symmetries of pseudomagnetic fields on graphene systems.