Department of Physics, Stanford University, California 94305, USA.
Phys Rev Lett. 2011 Nov 11;107(20):206602. doi: 10.1103/PhysRevLett.107.206602. Epub 2011 Nov 7.
We generalize the topological response theory of three-dimensional topological insulators (TI) to metallic systems-specifically, doped TI with finite bulk carrier density and a time-reversal symmetry breaking field near the surface. We show that there is an inhomogeneity-induced Berry phase contribution to the surface Hall conductivity that is completely determined by the occupied states and is independent of other details such as band dispersion and impurities. In the limit of zero bulk carrier density, this intrinsic surface Hall conductivity reduces to the half-integer quantized surface Hall conductivity of TI. Based on our theory we predict the behavior of the surface Hall conductivity for a doped topological insulator with a top gate, which can be directly compared with experiments.
我们将三维拓扑绝缘体（TI）的拓扑响应理论推广到金属体系——具体来说，是掺杂 TI 具有有限的体载流子密度和表面附近的时间反演对称性破缺场。我们表明，表面 Hall 电导率存在由不均匀性引起的Berry 位相贡献，该贡献完全由占据态决定，而与其他细节（如能带色散和杂质）无关。在零体载流子密度极限下，这个本征的表面 Hall 电导率简化为 TI 的半整数量子化的表面 Hall 电导率。基于我们的理论，我们预测了具有顶栅的掺杂拓扑绝缘体的表面 Hall 电导率的行为，这可以直接与实验进行比较。
