Department of Physics, University of Illinois, Urbana, 61801, USA.
Phys Rev Lett. 2011 Aug 12;107(7):075502. doi: 10.1103/PhysRevLett.107.075502. Epub 2011 Aug 9.
We consider the viscoelastic response of the electronic degrees of freedom in 2D and 3D topological insulators (TI's). Our primary focus is on the 2D Chern insulator which exhibits a bulk dissipationless viscosity analogous to the quantum Hall viscosity predicted in integer and fractional quantum Hall states. We show that the dissipationless viscosity is the response of a TI to torsional deformations of the underlying lattice geometry. The viscoelastic response also indicates that crystal dislocations in Chern insulators will carry momentum density. We briefly discuss generalizations to 3D which imply that time-reversal invariant TI's will exhibit a quantum Hall viscosity on their surfaces.
我们研究了二维和三维拓扑绝缘体（TI）中电子自由度的粘弹性响应。我们主要关注二维 Chern 绝缘体，它表现出与整数和分数量子 Hall 态中预测的量子 Hall 粘度类似的无耗散粘性。我们表明，无耗散粘性是 TI 对底层晶格几何的扭转变形的响应。粘弹性响应还表明，Chern 绝缘体中的晶体位错将携带动量密度。我们简要讨论了对三维的推广，这意味着时间反演不变的 TI 将在其表面表现出量子 Hall 粘度。
