Nematicity from mixed S +or-+dx 2-y 2 states in iron-based superconductors
2015 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 91, no 10, 104502Article in journal (Refereed) Published
We propose a novel mechanism for nematicity potentially relevant in some iron-based superconductors (SCs). We demonstrate that the mixed S +or-+dx 2-y 2 SC state is a physically accessible state and may emerge under generic conditions, lowering spontaneously the fourfold rotational symmetry C 4 to C 2. We provide a detailed study of the mixed S +or-+dx 2-y 2 nematic state including its behavior under a Zeeman field. As a fingerprint of this state, we predict at low temperatures a first-order Zeeman-field-induced transition from the mixed nematic SC phase to the pure dx 2-y 2 SC phase. The Zeeman field-temperature phase diagram for a nodeless mixed nematic state exhibits three distinct SC phases and a tetracritical point, remarkably reminiscent of the one observed in UPt 3. Our mechanism for nematicity may also be relevant for nonsuperconducting nematic states involving mixed S +or-+dx 2-y 2 spin/charge density waves.
Place, publisher, year, edition, pages
2015. Vol. 91, no 10, 104502
Theoretical or Mathematical/ charge density waves, critical points, high-temperature superconductors, mixed state, phase diagrams, pnictide superconductors, spin density waves, superconducting energy gap, superconducting transitions, Zeeman effect/ mixed S +or-+d x2-y2 nematic states, iron-based superconductors, fourfold rotational symmetry, first-order Zeeman-field-induced transition, Zeeman field-temperature phase diagram, tetracritical point, nonsuperconducting nematic states, mixed S +or-+d x2-y2 spin-charge density waves / A7460E Mixed state, H c2, surface sheath A7470V Perovskite phase and other high-temperature superconductors A7430J Electronic structure of superconductors A7145L Charge-density-wave systems A7170E Spin-orbit coupling, Zeeman, Stark and strain splitting (condensed matter) A7410 Superconducting critical temperature, occurrence A7430H Phase diagrams of superconductors A7440 Fluctuations and critical effects in superconductors/ Fe/ss Se/ss
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-249000DOI: 10.1103/PhysRevB.91.104502ISI: 000350994600004OAI: oai:DiVA.org:uu-249000DiVA: diva2:801637