Step-like features on caloric effects of graphenes

Abstract

We considered a graphene nano-ribbon with a longitudinal electric field (along $x$ direction) and a transversal magnetic field (along $z$ direction), and then observe (i) the electrocaloric effect ruled by an applied magnetic field and (ii) the magnetocaloric effect ruled by an applied electric field. We focused our attention to the limit of low temperatures, and then observed interesting step-like features. For each filled Landau level $n$, created by the applied magnetic field, both caloric effects increase proportionally to $n+1/2$; and this step measures either important graphene properties (like Fermi velocity) or quantum fundamental quantities (like Planck constant and magnetic flux quantum).