Electromagnetic wormholes and virtual magnetic monopoles from metamaterials

We describe new configurations of electromagnetic (EM) material parameters, the electric permittivity epsilon and magnetic permeability mu, which allow one to construct devices that function as invisible tunnels. These allow EM wave propagation between the regions at the two ends of a tunnel, but the tunnels themselves and the regions they enclose are not detectable to lateral EM observations. Such devices act as wormholes with respect to Maxwell's equations and effectively change the topology of space vis-a-vis EM wave propagation. We suggest several applications, including devices behaving as virtual magnetic monopoles, invisible cables, and scopes for MRI-assisted surgery.