Dual topological superconducting states in the layered titanium-based oxypnictide superconductor BaTi${}_2$Sb${}_2$O

Abstract

Topological superconductors have long been predicted to host Majorana zero modes which obey non-Abelian statistics and have potential for realizing non-decoherence topological quantum computation. However, material realization of topological superconductors is still a challenge in condensed matter physics. Utilizing high-resolution angle-resolved photoemission spectroscopy and first-principles calculations, we predict and then unveil the coexistence of topological Dirac semimetal and topological insulator states in the vicinity of Fermi energy ($E_F$) in the titanium-based oxypnictide superconductor BaTi${}_2$Sb${}_2$O. Further spin-resolved measurements confirm its spin-helical surface states around $E_F$, which are topologically protected and give an opportunity for realization of Majorana zero modes and Majorana flat bands in one material. Hosting dual topological superconducting states, the intrinsic superconductor BaTi${}_2$Sb${}_2$O is expected to be a promising platform for further investigation of topological superconductivity.

arXiv comment6 pages, 4 figures

References in corpus (68)

• Topological insulators and superconductors
• 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
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Angle-resolved photoemission spectroscopy of the cuprate superconductors
• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• Helical liquids and Majorana bound states in quantum wires
• New directions in the pursuit of Majorana fermions in solid state systems
• Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• A generic new platform for topological quantum computation using semiconductor heterostructures
• Search for Majorana fermions in superconductors
• Observation of Majorana Fermions in a Nb-InSb Nanowire-Nb Hybrid Quantum Device
• Topological superconductors: a review
• Majorana fermions in a tunable semiconductor device
• Observation of the fractional ac Josephson effect: the signature of Majorana particles
• Majorana Zero Modes and Topological Quantum Computation
• Exponential Protection of Zero Modes in Majorana Islands
• Majorana bound states in a coupled quantum-dot hybrid-nanowire system
• Superconductivity in CuxBi2Se3 and its implications for pairing in the undoped topological insulator
• Realizing Majorana zero modes in superconductor-semiconductor heterostructures
• Classification of stable three-dimensional Dirac semimetals with nontrivial topology
• Colloquium: Majorana Fermions in nuclear, particle and solid-state physics
• Introduction to topological superconductivity and Majorana fermions
• Topological Defects and Gapless Modes in Insulators and Superconductors
• Odd-Parity Topological Superconductors: Theory and Application to Cu${}_x$Bi${}_2$Se${}_3$
• Superconductor-Nanowire Devices from Tunneling to the Multichannel Regime: Zero-Bias Oscillations and Magnetoconductance Crossover
• Anomalous modulation of a zero bias peak in a hybrid nanowire-superconductor device
• Evidence for Majorana bound state in an iron-based superconductor
• Observation of topological superconductivity on the surface of an iron-based superconductor
• Topological Superconductivity in CuxBi2Se3
• Spin-resolved Andreev levels and parity crossings in hybrid superconductor-semiconductor nanostructures
• The Coexistence of Superconductivity and Topological Order in the Bi2Se3 Thin Films
• Symmetry and Topology in Superconductors - Odd-frequency pairing and edge states -
• Quantized Majorana conductance
• Majorana Fermions in Semiconductor Nanowires: Fundamentals, Modeling, and Experiment
• Observation of topological order in a Superconducting doped topological insulator (based on the Bi2Se3 class)
• Scaling of Majorana Zero-Bias Conductance Peaks
• Topological superconductivity in a van der Waals heterostructure
• Unconventional Josephson Effect in Hybrid Superconductor-Topological Insulator Devices
• Induced Superconductivity in the Quantum Spin Hall Edge
• Majorana Fermions and Topology in Superconductors
• Spin-Rotation Symmetry Breaking in the Superconducting State of CuxBi2Se3
• Fermi Surface Topological Invariants for Time Reversal Invariant Superconductors
• Observation of half-height magnetization steps in Sr2RuO4
• Zero-energy vortex bound state in the superconducting topological surface state of Fe(Se,Te)
• Topological odd-parity superconductors
• Multiple topological states in iron-based superconductors
• Thermodynamic evidence for nematic superconductivity in Cu${}_x$Bi${}_2$Se${}_3$
• Superconductivity with topological surface state in SrxBi2Se3
• Nearly quantized conductance plateau of vortex zero mode in an iron-based superconductor
• Zero-Energy Modes from Coalescing Andreev States in a Two-Dimensional Semiconductor-Superconductor Hybrid Platform
• Ballistic superconductivity in semiconductor nanowires
• Observation of half-integer level shift of vortex bound states in an iron-based superconductor
• Experimental Phase Diagram of a One-Dimensional Topological Superconductor
• Signature of Dispersing 1D Majorana Channels in an Iron-based Superconductor
• Fully gapped topological surface states in Bi${}_2$Se${}_3$ films induced by a d-wave high-temperature superconductor
• Majorana Fermions and Exotic Surface Andreev Bound States in Topological Superconductors: Application to CuxBi2Se3
• Edge states of Sr${}_2$RuO${}_4$ detected by in-plane tunneling spectroscopy
• Andreev reflection from non-centrosymmetric superconductors and Majorana bound state generation in half-metallic ferromagnets
• Topological superconductivity and Majorana fermions in half-metal / superconductor heterostructure
• Symmetry Protected Josephson Supercurrents in Three-Dimensional Topological Insulators
• Two types of Dirac-cone surface states on (111) surface of topological crystalline insulator SnTe
• Ba1-xNaxTi2Sb2O (0.0 <= x <= 0.33): A Layered Titanium-based Pnictide Oxide Superconductor
• Evidence for Helical Hinge Zero Modes in an Fe-Based Superconductor
• Topological Crystalline Superconductivity in Dirac Semimetal Phase of Iron-based Superconductors

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