"Oscillatory crossover from two-dimensional to three-dimensional topological insulators"

Chao-Xing Liu: HaiJun Zhang, Binghai Yan, Xiao-Liang Qi, Thomas Frauenheim, Xi Dai, Zhong Fang, and Shou-Cheng Zhang ; Phys. Rev. B , 01/19/10.

Additional Authors: HaiJun Zhang, Binghai Yan, Xiao-Liang Qi, Thomas Frauenheim, Xi Dai, Zhong Fang, and Shou-Cheng Zhang

Abstract:

We investigate the crossover regime from three-dimensional topological insulators Bi2Te3 and Bi2Se3 to two-dimensional topological insulators with quantum spin Hall effect when the layer thickness is reduced. Using both analytical models and first-principles calculations, we find that the crossover occurs in an oscillatory fashion as a function of the layer thickness, alternating between topologically trivial and nontrivial two-dimensional behavior.