Two-Dimensional In–Sb Compound on Silicon as a Quantum Spin Hall Insulator

Abstract

Two-dimensional (2D) topological insulator is a promising quantum phase for achieving dissipationless transport due to the robustness of the gapless edge states resided in the insulating gap providing realization of the quantum spin Hall effect. Searching for two-dimensional realistic materials that are able to provide the quantum spin Hall effect and possessing the feasibility of their experimental preparation is a growing field. Here we report on the two-dimensional (In, Sb)2[Formula: see text]2[Formula: see text] compound synthesized on Si(111) substrate and its comprehensive experimental and theoretical investigations based on an atomic-scale characterization by using scanning tunneling microscopy and angle-resolved photoelectron spectroscopy as well as ab initio density functional theory calculations identifying the synthesized 2D compound as a suitable system for realization of the quantum spin Hall effect without additional functionalization like chemical adsorption, applying strain, or gating.

Direct synthesis of metastable phases of 2D transition metal dichalcogenides

“…[19][20][21] Their chemical stability makes them more advantageous of the currently known large gap QSH insulators such as stanene 22 and two-dimensional In-Sb compounds which can be used in an inert atmosphere only. 23 On the other hand, it is predicted that a spontaneous symmetry breaking in the undistorted metallic 1T phase would open up a band gap and lead to the emergence of robust ferroelectricity in the novel 1T 00 0 phase. 24 Despite the rapid progress in investigating the properties of 1T(1T 0 ) phases of group VI TMDs over a small scale (about hundreds of nanometres over the basal plane), it is still quite arduous to obtain those phases as continuous over large areas.…”

Direct solution-phase synthesis of 1T’ WSe2 nanosheets

“…The 1T and 1T’ phases of group VI TMDs started to emerge only recently; however, compared to the semiconducting 2H phase, they have exhibited an exceptional performance for electrocatalytic hydrogen evolution and energy storage applications owing to the dramatically reduced charge transfer resistance 7 due to their metallic nature 8 . Moreover, 1T’ WSe 2 single layer is predicted to be a large gap quantum spin Hall (QSH) insulator suitable for application in spintronic devices 9 both operable at ambient temperature in contrast to the 1T’ WTe 2 10 and benefiting from chemical stability of the material compared to that of other currently known large gap QSH insulators such as stanene 11 and two-dimensional In-Sb compounds 12 existing in an inert atmosphere only.…”

Nanomaterials for Quantum Information Science and Engineering

“…Silicene, germanene, and stanene are elemental group-IV 2D materials with a honeycomb lattice like graphene, but the slightly buckled structure and greater atomic mass lead to greater SOC; these materials have been predicted as QSHIs with greater spin-orbit gaps than graphene [388][389][390] . Various other emerging 2D materials have been experimentally shown to be QSHIs: bilayer bismuth [391] ; antimonene [392] ; MBE-grown monolayer 1T'-WSe2 [393] ; a 2D In-Sb compound grown on Si [394] ; ZrTe5 [395] ; etc. Various other 2D QHSIs have been theoretically predicted [396][397][398][399] .…”