Year: 2026
Type: preprint
Abstract: The recent discovery of intrinsic superconductivity in stoichiometric FeTe films has renewed interest in the Te-rich end member of the iron chalcogenides for studies of unconventional and topological superconductivity, yet its intrinsic electronic structure remains unresolved. In this work, we combine molecular beam epitaxy, angle-resolved photoemission spectroscopy (ARPES), electrical transport measurements, density functional theory, and embedded dynamical mean-field theory to track the electronic reconstruction of 20-unit-cell FeTe films as Te annealing progressively removes excess interstitial Fe and drives the system from an antiferromagnetic metal to a superconductor. We find that this evolution is accompanied by recovered quasiparticle coherence, reduced electronic correlations, a Lifshitz transition, and a topological phase transition, yielding dxy-dominated hole and electron pockets that favor inter-pocket scattering. In addition, a shallow dxz/dyz-derived hole band located about 2 meV below the Fermi level may provide an incipient-band pairing channel, while scattering between the two electron pockets at M may offer additional pairing channels. High-resolution polarization-dependent laser ARPES measurements further reveal a topological surface state whose circular dichroism is consistent with the expected orbital-angular-momentum texture of stoichiometric FeTe. These results establish the intrinsic low-energy electronic structure of superconducting FeTe and identify the electronic states most relevant to superconductivity. The coexistence of intrinsic superconductivity and a topological surface state establishes stoichiometric FeTe as a promising platform for exploring topological superconductivity and possible Majorana bound states.
Source: arXiv (Cornell University)
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Gordon and Betty Moore Foundation, University of Pennsylvania, University of Chicago, Pennsylvania State University, Leverhulme Trust, Materials Research Science and Engineering Center, Harvard University, Office of Naval Research, Division of Materials Research
Awards: Exploring Emergent Magnetic Topological States in Three-Dimensional Magnetic Topological Insulator Multilayers, G2464805820, G2515106960, G2893699457, G3100489792, G3145663602, MIP: 2D Crystal Consortium (MIP-2DCC), G3829267213, G4653638168, G4742140246, Cui-Zu Chang Materials Synthesis Investigator, Disorder and the Emergence of Inhomogeneous Phases in Strongly Correlated Electron Systems, G7220896217, CAREER: Tuning Topology and Strong Correlations for the Next Generation of Topological Superconductors, G7683368480, G8848837166, MRSEC: Center for Nanoscale Science
OpenAlex ID: W7214011136