Bicephalous transformed media: concentrator versus rotator and cloak versus superscatterer.

Transformational optics allows for unprecedented control of light with cylindrical cloaks, concentrators, rotators and superscatterers. These are made of different heterogeneous anisotropic media. Can one cloak an s-polarized field and concentrate (or rotate) a p-polarized field with the same metamaterial (or vice versa)? We show the answer is positive provided the geometric transforms underpinning these functionalities take the same values on the outer boundary of what we call a bicephalous metamaterial. In this way, one can also make a metallic cylinder appear invisible for one light polarization, and larger for the other.