Hybrid symmetry epitaxy of superconducting Fe(Te,Se) film on a topological insulator

Abstract

It is challenging to grow an epitaxial four-fold compound superconductor (SC) on six-fold topological insulator (TI) platform due to stringent lattice-matching requirement. Here, we demonstrate that Fe(Te,Se) can grow epitaxially on a TI (Bi2Te3) layer due to accidental, uniaxial lattice match, which is dubbed as "hybrid symmetry epitaxy". This new growth mode is critical to stabilizing robust superconductivity with TC as high as 13 K. Furthermore, the superconductivity in this FeTe1-xSex/Bi2Te3 system survives in Te-rich phase with Se content as low as x = 0.03 but vanishes at Se content above x = 0.56, exhibiting a phase diagram that is quite different from that of the conventional Fe(Te,Se) systems. This unique heterostructure platform that can be formed in both TI-on-SC and SC-on-TI sequences opens a route to unprecedented topological heterostructures.

41 pages, 14 figures, accepted by Nano Letters

References in corpus (10)

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• Record-High Proximity-Induced Anomalous Hall Effect in (Bi${}_x$Sb${}_{1-x}$)2Te${}_3$ Thin Film Grown on CrGeTe${}_3$ Substrate
• Robust topological surface states of Bi2Se3 thin films on amorphous SiO2/Si substrate and a large ambipolar gating effect
• Superconductivity in the surface state of noble metal gold and its Fermi level tuning by EuS dielectric
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Cited by in corpus (18)

• Interface-Induced Superconductivity in Magnetic Topological Insulator-Iron Chalcogenide Heterostructures
• Monolayer superconductivity and tunable topological electronic structure at the Fe(Te,Se)/Bi2Te3 interface
• Dirac-Fermion-Assisted Interfacial Superconductivity in Epitaxial Topological Insulator/Iron Chalcogenide Heterostructures
• Molecular beam epitaxy of superconducting FeSe${}_x$Te${}_{1-x}$ thin films interfaced with magnetic topological insulators
• Superconducting four-fold Fe(Te,Se) film on six-fold magnetic MnTe via hybrid symmetry epitaxy
• Universal Superconductivity in FeTe and All-Iron-Based Ferromagnetic Superconductor Heterostructures
• Atomic-Layer-Controlled Magnetic Orders in MnBi2Te4-Bi2Te3 Topological Heterostructures
• Interfacially enhanced superconductivity in Fe(Te,Se)/Bi4Te3 heterostructures
• Resilient Growth of Highly Crystalline Topological Insulator-Superconductor Heterostructure Enabled by Ex-situ Nitride Film
• Evidence for a robust sign-changing s-wave order parameter in monolayer films of superconducting Fe (Se,Te)/Bi2Te3
• From classical to quantum regime of topological surface states via defect engineering
• Mystery of superconductivity in FeTe films and the role of neighboring layers
• Higher-order epitaxy: A pathway to suppressing structural instability and emergent superconductivity
• Control of nonreciprocal charge transport in topological insulator/superconductor heterostructures with Fermi level tuning and superconducting-layer thickness
• Proximity effect and inverse proximity effect in a topological-insulator/iron-based-superconductor heterostructure
• Interface-Enhanced Superconductivity in Ultrathin TiN Proximitized by Topological Insulators
• Ubiquity of rotational symmetry breaking in superconducting films, from Fe(Te,Se)/Bi${}_2$Te${}_3$ to Nb, and the effect of measurement geometry
• Unveiling In-Gap States and Majorana Zero Modes in Superconductor-Topological Insulator Bilayer model