关键词: topological insulator, weak anti-localization effect, $\alpha $-In$_{2}$Se$_{3}$, electrical transport characteristics

Abstract: Nonvolatile electric-field control of the unique physical characteristics of topological insulators (TIs) is essential for the fundamental research and development of practical electronic devices. Electrically tunable transport properties through gating materials have been extensively investigated. However, the relatively weak and volatile tunability limits its practical applications in spintronics. Here, we demonstrate the nonvolatile electric-field control of Bi$_{2}$Te$_{3}$ transport properties via constructing ferroelectric Rashba architectures, i.e., 2D Bi$_{2}$Te$_{3}/\alpha $-In$_{2}$Se$_{3}$ ferroelectric field-effect transistors. By switching the polarization states of $\alpha $-In$_{2}$Se$_{3}$, the Fermi level, resistance, Fermi wave vector, carrier mobility, carrier density and magnetoresistance (MR) of the Bi$_{2}$Te$_{3}$ film can be effectively modulated. Importantly, a shift of the Fermi level towards a band gap with a surface state occurs as switching to a negative polarization state, the contribution of the surface state to the conductivity then increases, thereby increasing the carrier mobility and electron coherence length significantly, resulting in the enhanced weak anti-localization (WAL) effect. These results provide a nonvolatile electric-field control method to tune the electronic properties of TI and can further extend to quantum transport properties.

Key words: topological insulator, weak anti-localization effect, $\alpha $-In$_{2}$Se$_{3}$, electrical transport characteristics