A realistic topological p-n junction at the Bi2Se3 （0001） surface based on planar twin boundary defects

作     者：Hugo Aramberri M. Carmen Munoz Jorge I. Cerda 

作者机构：Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) Cantoblanco Madrid 28049 Spain 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2017年第10卷第5期

页      面：1784-1793页

核心收录：

学科分类：0808[工学-电气工程] 07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the Spanish Ministry of Economy and Competitiveness through Grant 

主　　题：topological insulators,p n junctions,spintronics,electronic devices,twin boundaries 

摘      要：We propose a realistic topological p-n junction （TPNJ） by matching two Bi2Se3 （0001） slabs with opposite arrangements of planar twin boundary defects. The atomistic modeling of such a device leads to dislocation defects in the hexagonal lattice in several quintuple layers. Nevertheless, total energy calculations reveal that the interface relaxes, yielding a smooth geometrical transition that preserves the nearest-neighbors fcc-type geometry throughout these defect layers. The electronic, magnetic, and transport properties of the junction have then been calculated at the ab initio level under open boundary conditions, i.e., employing a thin-film geometry that is infinite along the electron transport direction. Indeed, a p-n junction is obtained with a built-in potential as large as 350 meV. The calculations further reveal the spin texture across the interface with unprecedented detail. As the main result, we obtain non-negligible transmission probabilities around the F point, which involve an electron spin-flip process while crossing the interface.