1210.4623 (Xiao Li et al.)

Coupling the valley degree of freedom to antiferromagnetic order    [PDF]

Xiao Li, Ting Cao, Qian Niu, Junren Shi, Ji Feng

In this paper, we develop the theory of spin and valley physics of an antiferromagnetic honeycomb lattice. We show that by coupling the valley degree of freedom to antiferromagnetic order, there is an emergent electronic degree of freedom characterized by the product of spin and valley indices, which leads to spin-valley dependent optical selection rule and Berry curvature-induced topological quantum transport. The domain walls of an antiferromagnetic honeycomb lattice harbors valley- protected edge states that support spin-dependent transport. Finally, we employ first principles calculations to show that the proposed optoelectronic properties can be realized in antiferromagnetic manganese chalcogenophosphates (MnPX3, X = S, Se) in monolayer form.

View original: http://arxiv.org/abs/1210.4623