Tuning the topological states in metal-organic bilayers

Abstract

We have investigated the energetic stability and the electronic properties of metal-organic topological insulators bilayers (BLs), $(M{C}_4{S}_4{)}_3$-BL, with M=Ni and Pt, using first-principles calculations and tight-binding model. Our findings show that $(M{C}_4{S}_4{)}_3$-BL is an appealing platform to perform electronic band structure engineering, based on the topologically protected chiral edge states. The energetic stability of the BLs is ruled by van der Waals interactions; being the AA stacking the energetically most stable one. The electronic band structure is characterized by a combination of bonding and anti-bonding kagome band sets (KBSs), revealing that $(Ni{C}_4{S}_4{)}_3$-BL presents a Z${}_2$-metallic phase, whereas $(Pt{C}_4{S}_4{)}_3$-BL may present both Z${}_2$-metallic phase or quantum spin Hall phase. Those non-trivial topological states were confirmed by the formation of chiral edge states in $(M{C}_4{S}_4{)}_3$-BL nanoribbons. We show that the localization of the edge states can be controlled with a normal external electric field, breaking the mirror symmetry. Hence, the sign of electric field selects in which layer each set of edge states are located. Such a control on the (layer) localization, of the topological edge states, bring us an additional and interesting degree of freedom to control the transport properties in layered metal-organic topological insulator.

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• Quantum Monte Carlo Calculation of the Binding Energy of Bilayer Graphene
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Cited by in corpus (9)

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• Double flat bands in kagome twisted bilayers
• Orbital pseudospin-momentum locking in two-dimensional chiral borophene
• Quantum anomalous Hall effect in metal-bis(dithiolene), magnetic properties, doping and interfacing graphene
• At the verge of topology: vacancy-driven quantum spin Hall in trivial insulators
• Engineering metal-$s{p}_{xy}$ Dirac bands on the oxidized SiC surface
• Emergent quasiparticles in Euclidean tilings
• Interacting Virtual Topological Phases in Defect-Rich 2D Materials