Magnetic, superconducting, and topological surface states on Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$

Abstract

The idea of employing non-Abelian statistics for error-free quantum computing ignited interest in recent reports of topological surface superconductivity and Majorana zero modes (MZMs) in FeTe${}_{0.55}$Se${}_{0.45}$. An associated puzzle is that the topological features and superconducting properties are not observed uniformly across the sample surface. Understanding and practical control of these electronic inhomogeneities present a prominent challenge for potential applications. Here, we combine neutron scattering, scanning angle-resolved photoemission spectroscopy (ARPES), and microprobe composition and resistivity measurements to characterize the electronic state of Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$. We establish a phase diagram in which the superconductivity is observed only at sufficiently low Fe concentration, in association with distinct antiferromagnetic correlations, while the coexisting topological surface state occurs only at sufficiently high Te concentration. We find that FeTe${}_{0.55}$Se${}_{0.45}$ is located very close to both phase boundaries, which explains the inhomogeneity of superconducting and topological states. Our results demonstrate the compositional control required for use of topological MZMs in practical applications.

Main text (18 pages, 5 figures, 50 references) combined with Supplementary (18 pages, 12 figures). Nat. Mater. (2021)

References in corpus (9)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Non-Abelian Anyons and Topological Quantum Computation
• Extreme Sensitivity of Superconductivity to Stoichiometry in FeSe (Fe1+dSe)
• Zero-energy vortex bound state in the superconducting topological surface state of Fe(Se,Te)
• Spin Gap and Resonance at the Nesting Wavevector in Superconducting FeSe0.4Te0.6
• Short-range incommensurate magnetic order near the superconducting phase boundary in Fe(1+d)Te(1-x)Se(x)
• Disappearance of static magnetic order and evolution of spin fluctuations in Fe${}_{1+\delta }$Se${}_x$Te${}_{1-x}$
• Evolution from incoherent to coherent electronic states and its implications to superconductivity in FeTe1-xSex
• On the interplay of paramagnetism and topology in the Fe-based High Tc Superconductors

Cited by in corpus (28)

• Non-Thermal Emergence of an Orbital-Selective Mott Phase in FeTe${}_{1-x}$Se${}_x$
• Correlation-Driven Electronic Reconstruction in FeTe${}_{1-x}$Se${}_x$
• Observation of Superconductivity Induced Ferromagnetism in an Fe-Chalcogenide Superconductor
• Revealing the Origin of Time-reversal Symmetry Breaking in Fe-chalcogenide Superconductor FeTe1-xSex
• Monolayer superconductivity and tunable topological electronic structure at the Fe(Te,Se)/Bi2Te3 interface
• Orbital Selective Mott Transition Effects and Non-Trivial Topology of Iron Chalcogenide
• Phase diagrams on composition-spread Fe${}_y$Te${}_{1-x}$Se${}_x$ films
• Origin of Topological Surface Superconductivity in FeSe${}_{0.45}$Te${}_{0.55}$
• Magnetic molecular orbitals in MnSi
• Molecular beam epitaxy of superconducting FeSe${}_x$Te${}_{1-x}$ thin films interfaced with magnetic topological insulators
• Direct observation of quantum anomalous vortex in Fe(Se,Te)
• Superconducting four-fold Fe(Te,Se) film on six-fold magnetic MnTe via hybrid symmetry epitaxy
• Parameter free treatment of a layered correlated van der Waals magnet: CrPS${}_4$
• Identifying Majorana vortex modes via non-local transport
• Competing topological superconducting phases in FeSe${}_{0.45}$Te${}_{0.55}$
• Resurgence of superconductivity and the role of $d_{xy}$ hole band in FeSe${}_{1-x}$Te${}_x$
• Anomalous Shiba states in topological iron-based superconductors
• Mystery of superconductivity in FeTe films and the role of neighboring layers
• In-situ electrical and thermal transport properties of FeySe1-xTex films with ionic liquid gating
• On the signatures of non-topological patches on the surface of topological insulators
• Higher-order epitaxy: A pathway to suppressing structural instability and emergent superconductivity
• Topological superconductivity driven by correlations and linear defects in multiband superconductors
• $\mathcal{N}=4$ chiral superconductivity in moiré transition metal dichalcogenides
• Anomalous Shiba spectrum and superconductivity induced magnetic interactions in materials with topological band inversion
• Fe${}_{1+y}$Te${}_x$Se${}_{1-x}$: a delicate and tunable Majorana material
• Acoustic lattice instabilities at the magneto-structural transition in Fe${}_{1.057(7)}$Te
• Symmetry-breaking-induced topology in FeSe
• Evolution of the intertwining correlated topological phases in iron-based superconductor Fe(Te,Se)