Majorana Zero Modes and Topological Nature in Bi2Ta3S6-family Superconductors

Abstract

In this work, we report that Bi2Ta3S6-family superconductors exhibit nontrivial band topology. They possess a natural quantum-well structure consisting of alternating stacks of TaS2 and honeycomb Bi layers, which contribute superconducting and topological properties, respectively. Symmetry-based indicators $({\mathbb{Z}}_4;{\mathbb{Z}}_2{\mathbb{Z}}_2{\mathbb{Z}}_2)=(2;000)$ reveal that the topological nature arises entirely from the Bi layers, which belong to a quantum spin Hall phase characterized by a $p_x-p_y$ model on a honeycomb lattice. The topological zigzag (ZZ) and armchair (AC) edge states are obtained. Using VASP2KP, the in-plane $g$ factors of these topological edge states are computed from the ab initio calculations: $g_{x/y}^{\mathrm{ZZ}}=2.07/1.60$ and $g_{x/y}^{\mathrm{AC}}=0.50/0.06$. The strong anisotropy of the edge-state $g$ factors allows us to explore Majorana zero modes in the Bi monolayer on a superconductor, which can be obtained by exfoliation or molecular beam epitaxy. The relaxed structures of the Bi2Ta3Se6, Bi2Nb3S6 and Bi2Nb3Se6 are obtained. Their superconducting transition temperature $T_c$ are estimated based on the electron-phonon coupling and the McMillan formula. Furthermore, using the experimental superconducting gap $\Delta$ and the computed $g$ factors, we obtain the phase diagram, which shows that the in-plane field $B_y>2.62\mathrm{T}$ can generate corner Majorana zero modes in the Bi monolayer of the superconductor Bi2Ta3S6. A similar paradigm also applies to the Bi2Ta3S6 bulk with the emergence of Majorana hinge states. These natural quantum-well superconductors therefore offer ideal platforms for exploring topological superconductivity and Majorana zero modes.

arXiv comment5 pages, 5 figures

References in corpus (64)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Topological Insulators
• Topological insulators and superconductors
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Fault-tolerant quantum computation by anyons
• Non-Abelian Anyons and Topological Quantum Computation
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Unpaired Majorana fermions in quantum wires
• Topological Insulators with Inversion Symmetry
• New directions in the pursuit of Majorana fermions in solid state systems
• Non-Abelian statistics and topological quantum information processing in 1D wire networks
• Bismuthene on a SiC Substrate: A Candidate for a New High-Temperature Quantum Spin Hall Paradigm
• Josephson Current and Noise at a Superconductor-Quantum Spin Hall Insulator-Superconductor Junction
• Strongly enhanced charge-density-wave order in monolayer NbSe${}_2$
• Colloquium: Majorana Fermions in nuclear, particle and solid-state physics
• Symmetry-based Indicators of Band Topology in the 230 Space Groups
• Evidence for Majorana bound state in an iron-based superconductor
• Observation of topological superconductivity on the surface of an iron-based superconductor
• Topological Superconductivity and Superfluidity
• Topological classification of crystalline insulators through band structure combinatorics
• Observation of Majorana fermions with spin selective Andreev reflection in the vortex of topological superconductor
• Majorana mode in vortex core of Bi2Te3/NbSe2 topological insulator-superconductor heterostructure
• The Coexistence of Superconductivity and Topological Order in the Bi2Se3 Thin Films
• Chiral Topological Superconductor From the Quantum Hall State
• Higher-order topological insulators and superconductors protected by inversion symmetry
• Higher-Order Topology, Monopole Nodal Lines, and the Origin of Large Fermi Arcs in Transition Metal Dichalcogenides XTe${}_2$ (X=Mo,W)
• Quantitative mappings between symmetry and topology in solids
• Majorana corner modes in a high-temperature platform
• Symmetry indicators and anomalous surface states of topological crystalline insulators
• Topological nature of FeSe${}_{0.5}$Te${}_{0.5}$ superconductor
• Zero-energy vortex bound state in the superconducting topological surface state of Fe(Se,Te)
• Topological superconductivity on the surface of Fe-based superconductors
• Multiple topological states in iron-based superconductors
• High-Temperature Majorana Corner States
• Robust and clean Majorana zero mode in the vortex core of high-temperature superconductor (Li0.84Fe0.16)OHFeSe
• Chiral topological superconductor and half-integer conductance plateau from quantum anomalous Hall plateau transition
• Observation of half-integer level shift of vortex bound states in an iron-based superconductor
• Signature of Dispersing 1D Majorana Channels in an Iron-based Superconductor
• Majorana corner states in a two-dimensional magnetic topological insulator on a high-temperature superconductor
• Higher Order Topology and Nodal Topological Superconductivity in Fe(Se,Te) Heterostructures
• Helical Hinge Majoranas in Iron-Based Superconductors
• Topological Characters in Fe(Te${}_{1-x}$Se${}_x$) thin films
• In-plane Zeeman field induced Majorana corner and hinge modes in an $s$-wave superconductor heterostructure
• Ordered and tunable Majorana-zero-mode lattice in naturally strained LiFeAs
• New class of topological superconductors protected by magnetic group symmetries
• FeTe${}_{1-x}$Se${}_x$ monolayer films: towards the realization of high-temperature connate topological superconductivity
• Quantum anomalous vortex and Majorana zero mode in iron-based superconductor Fe(Te,Se)
• Intrinsic Time-reversal-invariant Topological Superconductivity in Thin Films of Iron-based Superconductors
• Helical Dirac-Majorana interferometer in a superconductor-topological insulator sandwich structure
• Nontrivial Quantum Geometry and the Strength of Electron-Phonon Coupling
• Interface-Induced Superconductivity in Magnetic Topological Insulator-Iron Chalcogenide Heterostructures
• Valley-polarized quantum anomalous Hall phases and tunable topological phase transitions in half-hydrogenated Bi honeycomb monolayers
• Proximity-effect-induced Superconducting Gap in Topological Surface States - A Point Contact Spectroscopy Study of NbSe2/Bi2Se3 Superconductor-Topological Insulator Heterostructures
• Competing Vortex Topologies in Iron-based Superconductors
• Topological Vortex Phase Transitions in Iron-Based Superconductors
• VASP2KP: kp models and Lande g-factors from ab initio calculations
• Large shift current, $\pi$ Zak phase and unconventional nature in Se and Te
• Double Majorana vortex zero modes in superconducting topological crystalline insulators with surface rotation anomaly
• Superconductivity in unconventional metals
• Visualization of Skyrmion-Superconducting Vortex Pairs in a Chiral-Magnet-Superconductor Heterostructure
• Topological superconductor candidates PdBi${}_2$Te${}_4$ and PdBi${}_2$Te${}_5$ from a generic ab initio strategy
• Majorana corner modes in unconventional monolayers of the 1T-PtSe2 family
• Investigating the superconducting state of 2$H$-NbS${}_2$ as seen by the vortex lattice
• Quantized Quadrupole Superconductors

Cited by in corpus (1)

• Growth and hydrostatic-pressure study of a type-II superconductor Bi${}_2$Ta${}_3$S${}_6$ single crystal