Fractional topological insulators.
We analyze generalizations of two-dimensional topological insulators which can be realized in interacting, time reversal invariant electron systems. These states, which we call fractional topological insulators, contain excitations with fractional charge and statistics in addition to protected edge modes. In the case of s(z) conserving toy models, we show that a system is a fractional topological insulator if and only if sigma(sH)/e* is odd, where sigma(sH) is the spin-Hall conductance in units of e/2pi, and e* is the elementary charge in units of e.
Levin
Michael
M
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Stern
Ady
A