Tamm states in one-dimensional photonic crystals containing left-handed materials

We present a theoretical study of electromagnetic surface waves localized at an interface separating a conventional uniform medium and a semi-infinite one-dimensional photonic crystal made of alternate left-handed metamaterial and right-handed material, which we refer to as left-handed photonic crystal. We find unusual type of surface mode's structure, the so-called surface Tamm states and demonstrate that the presence of metamaterial in the photonic crystal structure allows for a flexible control of the dispersion properties of surface states, and can support the Tamm states with a backward energy flow and a vortex-like structure.