Exotic Topological Insulator States and Topological Phase Transitions in Sb2Se3鈥揃i2Se3 Heterostructures

详细信息    查看全文

• 作者：Qianfan Zhang ; Zhiyong Zhang ; Zhiyong Zhu ; Udo Schwingenschl枚gl ; Yi Cui
• 刊名：ACS Nano
• 出版年：2012
• 出版时间：March 27, 2012
• 年：2012
• 卷：6
• 期：3
• 页码：2345-2352
• 全文大小：1046K
• 年卷期：v.6,no.3(March 27, 2012)
• ISSN：1936-086X

文摘

Topological insulator is a new state of matter attracting tremendous interest due to its gapless linear dispersion and spin momentum locking topological states located near the surface. Heterostructures, which have traditionally been powerful in controlling the electronic properties of semiconductor devices, are interesting for topological insulators. Here, we studied the spatial distribution of the topological state in Sb₂Se₃鈥揃i₂Se₃ heterostructures by first-principle simulation and discovered that an exotic topological state exists. Surprisingly, the state migrates from the nontrivial Bi₂Se₃ into the trivial Sb₂Se₃ region and spreads across the entire Sb₂Se₃ slab, extending beyond the concept of 鈥渟urface鈥?state while preserving all of the topological surface state characteristics. This unusual topological state arises from the coupling between different materials and the modification of electronic structure near Fermi energy. Our study demonstrates that heterostructures can open up opportunities for controlling the real-space distribution of the topological state and inducing quantum phase transitions between topologically trivial and nontrivial states.

Keywords:

topological insulator; heterostructure; topological state; first-principle simulation; spin鈭抩rbit coupling; quantum phase transition