We demonstrate a new quantum state of matter---valley-polarized quantum anomalous Hall effect in monolayer silicene. In the presence of extrinsic Rashba spin-orbit coupling and exchange field, monolayer silicene can host a quantum anomalous-Hall state with Chern number C=2. We find that through tuning Rashba spin-orbit coupling, a topological phase transition gives rise to a valley polarized quantum anomalous Hall state, i.e. a quantum state which exhibits electronic properties of both quantum valley-Hall effect (valley Chern number C_V=3) and quantum anomalous Hall effect with C=-1.
@article{arxiv.1304.8076,
title = {Valley-Polarized Quantum Anomalous-Hall Effects in Silicene},
author = {Hui Pan and Zhenshan Li and Cheng-Cheng Liu and Guobao Zhu and Zhenhua Qiao and Yugui Yao},
journal= {arXiv preprint arXiv:1304.8076},
year = {2014}
}