Giant Faraday and Kerr rotation with strained graphene

Polarized electromagnetic waves passing through (reflected from) a dielectric medium parallel to a magnetic field undergo Faraday (Kerr) rotation of their polarization. Recently, Faraday rotation angles as much as 0.1 rad were observed for terahertz waves propagating through graphene over a SiC substrate. We show that the same effect is observable with the magnetic field replaced by an in-plane strain field which induces a pseudomagnetic field in graphene. With two such sheets a rotation of pi/4 can be achieved, which is the required rotation for an optical diode. Similarly a Kerr rotation of 1/4 rad is predicted from a single reflection from a strained graphene sheet. (C) 2012 Optical Society of America