2023 article

Dual Topology of Dirac Electron Transport and Photogalvanic Effect in Low-Dimensional Topological Insulator Superlattices

Xue, H.-P., Sun, R., Yang, X., Comstock, A., Liu, Y., Ge, B., … Cheng, Z.-H. (2023, January 18). ADVANCED MATERIALS.

By: H. Xue*, R. Sun n, X. Yang*, A. Comstock n, Y. Liu*, B. Ge*, J. Liu*, Y. Wei* ...

author keywords: circularly polarized photogalvanic effect; dual topological insulators; linearly polarized photogalvanic effect; quantum transport
Source: Web Of Science
Added: February 6, 2023

Dual topological insulators, simultaneously protected by time-reversal symmetry and crystalline symmetry, open great opportunities to explore different symmetry-protected metallic surface states. However, the conventional dual topological states located on different facets hinder integration into planar opto-electronic/spintronic devices. Here, dual topological superlattices (TSLs) Bi2Se3-(Bi2/Bi2Se3)N with limited stacking layer number N are constructed. Angle-resolved photoelectron emission spectra of the TSLs identify the coexistence and adjustment of dual topological surface states on Bi2Se3 facet. The existence and tunability of spin-polarized dual-topological bands with N on Bi2Se3 facet result in an unconventionally weak antilocalization effect (WAL) with variable WAL coefficient α (maximum close to 3/2) from quantum transport experiments. Most importantly, it is identified that the spin-polarized surface electrons from dual topological bands exhibit circularly and linearly polarized photogalvanic effect (CPGE and LPGE). It is anticipated that the stacked dual-topology and stacking layer number controlled bands evolution provide a platform for realizing intrinsic CPGE and LPGE. The results show that the surface electronic structure of the dual TSLs is highly tunable and well-regulated for quantum transport and photoexcitation, which shed light on engineering for opto-electronic/spintronic applications.