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.