Edge states at nematic domain walls in FeSe films

Abstract

Quantum spin Hall (QSH) effect is an intriguing phenomenon arising from the helical edge states in two-dimensional topological insulators. We use molecular beam epitaxy (MBE) to prepare FeSe films with atomically sharp nematic domain boundaries, where tensile strains, nematicity suppression and topological band inversion are simultaneously achieved. Using scanning tunneling microscopy (STM), we observe edge states at the Fermi level that spatially distribute as two distinct strips in the vicinity of the domain boundaries. At the endpoint of the boundaries, a bound state at the Fermi level is further observed. The topological origin of the edge states is supported by density functional theory calculations. Our findings not only demonstrate a candidate for QSH states, but also provide a new pathway to realize topological superconductivity in a single-component film.

References in corpus (9)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Crystalline Insulators
• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• Antiferromagnetic topological insulators
• Nematic and meta-nematic transitions in the iron pnictides
• Reconstruction of Band Structure Induced by Electronic Nematicity in an FeSe Superconductor
• Topological Phases in the Single-Layer FeSe
• Quantum Spin Hall Effect in IV-VI Topological Crystalline Insulators

Cited by in corpus (13)

• On the Remarkable Superconductivity of FeSe and its Close Cousins
• Nanoscale decoupling of electronic nematicity and structural anisotropy in FeSe thin films
• Fragile topologically flat band in the checkerboard antiferromagnetic monolayer FeSe
• Quantum spin Hall effect protected by spin U(1) quasisymmetry
• Atomically sharp 1D interfaces in 2D lateral heterostructures of VSe${}_2$-NbSe${}_2$ monolayers
• Tomonaga Luttinger liquid in the topological edge channel of multilayer FeSe
• Nanoscale visualization of the thermally-driven evolution of antiferromagnetic domains in FeTe thin films
• Ubiquitous stripe phase and enhanced electron pairing in interfacial high-Tc superconductor FeSe/BaTiO${}_3$
• Rotation of the dislocation grid in multilayer FeSe films and visualization of electronic nematic domains via orbital-selective tunneling
• Spin-flip Scattering at a Chiral Interface of Helical Chains
• Atomic-scale imaging of electronic nematicity in ferropnictides
• Dual Enhancement of Superconductivity in FeSe/SrTiO3 via Orbital and Correlation Synergy
• Symmetry-breaking-induced topology in FeSe