Layer dependent topological phases and transitions in TaRhTe${}_4$: From monolayer and bilayer to bulk

Abstract

The recently synthesized ternary quasi-2D material TaRhTe${}_4$ is a bulk Weyl semimetal with an intrinsically layered structure, which poses the question how the topology of its electronic structure depends on layers separations. Experimentally these separations may be changed for instance by intercalation of the bulk, or by exfoliation to reach monolayer or few-layer structures. Here we show that in the monolayer limit a quantum spin Hall insulator (QSHI) state emerges, employing density functional calculations as well as a minimal four-orbital tight-binding model that we develop. Even for weak spin-orbit couplings the QSHI is present, which has an interesting edge state that features Rashba-split bands with quadratic band minima. Further we find that a weak topological insulator (WTI) manifests in the bilayer system due to sizable intralayer hopping, contrary to the common lore that only weak interlayer interactions between stacked QSHIs lead to WTIs. Stacked bilayers give rise to a phase diagram as function of the interlayer separation that comprises a Weyl semimetal, WTI and normal insulator phases. These insights on the evolution of topology with dimension can be transferred to the family of layered ternary transition metal tellurides.

arXiv comment22 pages, 14 figures

References in corpus (54)

• Topological Insulators
• Topological insulators and superconductors
• Quantum Spin Hall Effect in Graphene
• $Z_2$ Topological Order and the Quantum Spin Hall Effect
• Layer-dependent Ferromagnetism in a van der Waals Crystal down to the Monolayer Limit
• Electronic Structure of Pyrochlore Iridates: From Topological Dirac Metal to Mott Insulator
• Topological Insulators in Three Dimensions
• Weyl and Dirac Semimetals in Three Dimensional Solids
• Topological Insulators with Inversion Symmetry
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Classification of topological insulators and superconductors in three spatial dimensions
• Type-II Weyl Semimetals
• Topological invariants of time-reversal-invariant band structures
• Weyl Semimetal in a Topological Insulator Multilayer
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• Experimental discovery of Weyl semimetal TaAs
• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Observation of Weyl nodes in TaAs
• Time Reversal Polarization and a Z_2 Adiabatic Spin Pump
• An equivalent expression of Z2 Topological Invariant for band insulators using Non-Abelian Berry's connection
• Experimental observation of topological Fermi arcs in type-II Weyl semimetal MoTe2
• Topological insulators in twisted transition metal dichalcogenide homobilayers
• Quantized circular photogalvanic effect in Weyl semimetals
• Unique thickness-dependent properties of the van der Waals interlayer antiferromagnet $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$ films
• Computing topological invariants without inversion symmetry
• Observation of the Type-II Weyl Semimetal Phase in MoTe2
• Gated Silicene as a tunable source of nearly 100% spin-polarized electrons
• Weyl Semimetals, Fermi Arcs and Chiral Anomalies (A Short Review)
• Accurate Measurement of the Cleavage Energy of Graphite
• A Rigorous Method of Calculating Exfoliation Energies from First Principles
• Observation of Fermi Arcs in Type-II Weyl Semimetal Candidate WTe2
• Interlayer binding energy of graphite -- A direct experimental determination
• On the $Z_2$ classification of Quantum Spin Hall Models
• Room temperature nonlinear Hall effect and wireless RF rectification in Weyl semimetal TaIrTe4
• TaIrTe4 a ternary Type-II Weyl semi-metal
• The strong side of weak topological insulators
• Spectroscopic Evidence of Type II Weyl Semimetal State in WTe2
• Stacked topological insulator built from bismuth-based graphene sheet analogues
• Imaging Quantum Spin Hall Edges in Monolayer WTe2
• Transport in two-dimensional topological materials: recent developments in experiment and theory
• Observation of Fermi arc spin texture in TaAs
• Experimental realization of type-II Weyl state in non-centrosymmetric TaIrTe${}_4$
• Topological aspects of quantum spin Hall effect in graphene: Z${}_2$ topological order and spin Chern number
• Van der Waals Stacking Induced Topological Phase Transition in Layered Ternary Transition Metal Chalcogenides
• Transition between strong and weak topological insulator in ZrTe${}_5$ and HfTe${}_5$
• Tunable interlayer magnetism and band topology in van der Waals heterostructures of MnBi2Te4-family materials
• Half quantum spin Hall effect on the surface of weak topological insulators
• The influence of lattice termination on the edge states of the quantum spin Hall insulator monolayer $1T^{\prime }$-WTe${}_2$
• Custodial glide symmetry of quantum spin Hall edge modes in WTe${}_2$ monolayer
• Quantum spin Hall effect in monolayer and bilayer TaIrTe${}_4$
• Layered van der Waals topological metals of TaTMTe4 (TM = Ir, Rh, Ru) family
• Realistic tight-binding model for monolayer transition metal dichalcogenides in 1T' structure