1206.3650 (M. Tahir et al.)

Quantum spin/valley Hall effect and topological insulator phase
transitions in silicene    [PDF]

M. Tahir, A. Manchon, K. Sabeeh, U. Schwingenschlogl

We present a theoretical realization of quantum spin and quantum valley Hall effects in silicene. We show that combination of an electric field and intrinsic spin-orbit interaction leads to quantum phase transitions at the charge neutrality point. This phase transition from a two dimensional topological insulator to a trivial insulating state is accompanied by a quenching of the quantum spin Hall effect and the onset of a quantum valley Hall effect, providing a tool to experimentally tune the topological state of silicene. In contrast to graphene and other conventional topological insulators, the proposed effects in silicene are accessible to experiments.

View original: http://arxiv.org/abs/1206.3650