Symmetry-breaking-induced topology in FeSe

Abstract

FeSe has been one of the most intensively studied iron-based superconductors over the past two decades, exhibiting a wide range of phenomena such as unconventional superconductivity, nematic order, magnetism, orbital-selective correlations, and structural phase transitions. While topologically non-trivial phases have been identified in certain cases -- such as Te-doped FeSe and monolayer FeSe -- topology in bulk FeSe has largely remained unexplored. In this work, we propose a new route to realize topological phases directly in bulk FeSe. We demonstrate that breaking the tetragonal $C_4$ rotational symmetry, thereby lowering the crystal symmetry, can drive FeSe into a strong topological insulating phase. To support this, we perform density functional theory calculations and analyze the band structure using Topological Quantum Chemistry and symmetry-based indicators. Our results show that both uniaxial strain and temperature-induced structural changes lead to non-trivial band topology. Moreover, incorporating electronic correlations through dynamical mean field theory reveals that the topological characteristics near the Fermi level remain robust, as the relevant bands experience only moderate renormalization. These findings highlight strain as a promising mechanism to induce topological phases in FeSe

9 pages, 5 figures

References in corpus (33)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Non-Abelian Anyons and Topological Quantum Computation
• Superconductivity at 36 K in beta-Fe1.01Se with the compression of the interlayer separation under pressure
• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• Orbital-driven nematicity in FeSe
• Ironing out the details of unconventional superconductivity
• Double crystallographic groups and their representations on the Bilbao Crystallographic Server
• Magnetic Topological Quantum Chemistry
• Zero-energy vortex bound state in the superconducting topological surface state of Fe(Se,Te)
• Building Blocks of Topological Quantum Chemistry: Elementary Band Representations
• Origin of the tetragonal-to-orthorhombic (nematic) phase transition in FeSe: a combined thermodynamic and NMR study
• Theoretical evidence for strong correlations and incoherent metallic state in FeSe
• Nematicity, magnetism and superconductivity in FeSe
• The key ingredients of the electronic structure of FeSe
• On the Remarkable Superconductivity of FeSe and its Close Cousins
• The origin of nematic order in FeSe
• Pressure-induced antiferromagnetic transition and phase diagram in FeSe
• Formation of Hubbard-like bands as a fingerprint of strong electron-electron interactions in FeSe
• Evidence for Higher order topology in Bi and Bi${}_{0.92}$Sb${}_{0.08}$
• Effects of strain on the electronic structure, superconductivity, and nematicity in FeSe studied by angle-resolved photoemission spectroscopy
• Unified picture of the doping dependence of superconducting transition temperatures in alkali metal/ammonia intercalated FeSe
• Magnetic, superconducting, and topological surface states on Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$
• Strain-tuning of nematicity and superconductivity in single crystals of FeSe
• Interplay of nematic and magnetic orders in FeSe under pressure
• Fragile topologically flat band in the checkerboard antiferromagnetic monolayer FeSe
• Edge states at nematic domain walls in FeSe films
• Non-local $d_{xy}$ nematicity and the missing electron pocket in FeSe
• Correlation-corrected band topology and topological surface states in iron-based superconductors
• Orbital Selective Mott Transition Effects and Non-Trivial Topology of Iron Chalcogenide
• Origin of Topological Surface Superconductivity in FeSe${}_{0.45}$Te${}_{0.55}$
• Basic electronic properties of iron selenide under variation of structural parameters
• Accurate modeling of FeSe with screened Fock exchange and Hund's metal correlations