Centre for the Physics of Materials and Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada.
Nano Lett. 2011 May 11;11(5):2088-91. doi: 10.1021/nl200584f. Epub 2011 Apr 15.
We report density functional theory analysis of the electronic and quantum transport properties of Bi(2)Se(3) topological insulator, focusing on the helical surface states at the Fermi level E(F). The calculated Dirac point and the tilt angle of the electron spin in the helical states are compared quantitatively with the experimental data. The calculated conductance near E(F) shows a V-shaped spectrum, consistent with STM measurements. The spins in the helical states at E(F) not only tilts out of the two-dimensional plane, they also oscillate with a 3-fold symmetry going around the two-dimensional Brillouin zone. The helical states penetrate into the material bulk, where the first quintuple layer contributes 70% of the helical wave functions.
我们报告了 Bi(2)Se(3)拓扑绝缘体的电子和量子输运性质的密度泛函理论分析，重点关注费米能级 E(F)处的螺旋表面态。计算出的狄拉克点和螺旋态中电子自旋的倾斜角与实验数据进行了定量比较。在 E(F)附近计算出的电导呈现出 V 形谱，与 STM 测量结果一致。在 E(F)处的螺旋态中的自旋不仅倾斜出二维平面，它们还以三重对称的方式围绕二维布里渊区进行振荡。螺旋态穿透到材料体相中，其中第一层五倍层贡献了 70%的螺旋波函数。
