Over
the past few years, the physics of low dimensional electronic systems
has been revolutionized by the discovery of materials with very unusual
electronic structures. Among these, graphene has taken center stage due to its relativistic-like
electron dynamics and potential applications in nanotechnology. Moreover, the recent discovery that hexagonal boron nitride (hBN) is a
nearly-ideal substrate for high mobility graphene devices has enabled a
new generation of quantum transport and optoelectronic experiments in graphene-based materials. In this
talk I will review our recent experiments on graphene on hBN devices,
where we explore different aspects of the "Dirac-ness" of charge
carriers in graphene: from novel optoelectronic phenomena to a new type
of quantum spin Hall effect.