Shadow gap in the over-doped (Ba${}_{1-x}$K${}_x$)Fe${}_2$As${}_2$ compound

Abstract

The electron band around $M$ point in (Ba${}_{1-x}$K${}_x$)Fe${}_2$As${}_2$ compound -- completely lifted above the Fermi level for $x>0.7$ and hence has no Fermi Surface (FS) -- can still form an isotropic s-wave gap (${\Delta }_e$) and it is the main pairing resource generating an s-wave gap (${\Delta }_h$) with an opposite sign on the hole pocket around $\Gamma$ point. The electron band developing the SC order parameter ${\Delta }_e$ but having no FS displays a {\it shadow gap} feature which will be easily detected by various experimental probes such as angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscope (STM). Finally, the formation of the nodal gap ${\Delta }_{nodal}$ with $A_{1g}$ symmetry on the other hole pocket with a larger FS is stabilized due to the balance of the interband pairing interactions from the main hole band gap ${\Delta }_h=+\Delta$ and the hidden electron band gap ${\Delta }_e=-\Delta$.

5 pages, 4 figures

References in corpus (9)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Phase Diagram of Ba1-xKxFe2As2
• Universal heat conduction in the iron-arsenide superconductor KFe2As2 : Evidence of a d-wave state
• Imaging superconducting vortex core and lattice with the scanning tunneling microscope
• Possible pairing states of the Fe-based superconductors
• Universality of superconducting gaps in overdoped Ba0.3K0.7Fe2As2 observed by angle-resolved photoemission spectroscopy
• Incommensurate spin fluctuations in hole-overdoped superconductor KFe2As2
• Isotope effect and the role of phonon in the Fe-based superconductors
• Are there nodes in LaFePO, BaFe${}_2$(AsP)${}_2$, and KFe${}_2$As${}_2$ ?

Cited by in corpus (36)

• Iron-Based Superconductors: current status of materials and pairing mechanism
• Possible high $T_c$ Superconductivity in La${}_3$Ni${}_2$O${}_7$ under High Pressure through Manifestation of a Nearly-Half-Filled Bilayer Hubbard Model
• Using Gap Symmetry and Structure to Reveal the Pairing Mechanism in Fe-based Superconductors
• On the Remarkable Superconductivity of FeSe and its Close Cousins
• Electron pairing in the presence of incipient bands in iron-based superconductors
• Finite energy spin fluctuation as a pairing glue in systems with coexisting electron and hole bands
• Strong Correlations, Strong Coupling and s-wave Superconductivity in Hole-doped BaFe2As2 Single Crystals
• Superconducting Properties of the $s^{\pm }$-wave state: Fe-based superconductors
• Surface electronic structure and evidence of plain s-wave superconductivity in (Li0.8Fe0.2)OHFeSe
• Superconductivity across Lifshitz transition and anomalous insulating state in surface K-dosed (Li0.8Fe0.2OH)FeSe
• Unconventional multi-band superconductivity in bulk SrTiO${}_3$ and LaAlO${}_3$/SrTiO${}_3$ interfaces
• Ab initio Study of Cross-Interface Electron-Phonon Couplings in FeSe Thin Films on SrTiO${}_3$ and BaTiO${}_3$
• Multiband full-bandwidth anisotropic Eliashberg theory of interfacial electron-phonon coupling and high-T${}_c$ superconductivity in FeSe/SrTiO${}_3$
• Wide applicability of high $T_c$ pairing originating from coexisting wide and incipient narrow bands in quasi one dimension
• Superconducting mechanism for the cuprate Ba${}_2$CuO${}_{3+\delta }$ based on a multiorbital Lieb lattice model
• Quantum geometric effect on Fulde-Ferrell-Larkin-Ovchinnikov superconductivity
• Strongly enhanced superconductivity due to finite energy spin fluctuations induced by an incipient band : a FLEX study on the bilayer Hubbard model with vertical and diagonal interlayer hoppings
• Possible high-$T_c$ superconductivity due to incipient narrow bands originating from hidden ladders in Ruddlesden-Popper compounds
• Many-variable variational Monte-Carlo study of superconductivity in two-band Hubbard models with an incipient band
• Phonon linewidth due to electron-phonon interactions with strong forward scattering in FeSe thin films on oxide substrates
• Designing nickelate superconductors with $d^8$ configuration exploiting mixed-anion strategy
• Phonon Boost Effect on the $S^{\pm }$-wave Superconductor with Incipient Band
• Real-space BCS-BEC crossover in FeSe monolayer
• Enhanced superconductivity in FeSe/SrTiO${}_3$ from the combination of forward scattering phonons and spin fluctuations
• The Coulomb problem in iron based superconductors
• Hidden sign-changing $s$-wave superconductivity in monolayer FeSe
• Possible counterintuitive enhancement of superconductivity in ladder-type cuprates by longitudinal compression
• Hidden robust presence of a hole Fermi surface in a heavily electron doped iron based superconductor LaFe${}_2$As${}_2$
• Impact of disorder on the superconducting transition temperature near a Lifshitz transition
• Strong Landau-quantization effects in high-magnetic-field superconductivity of a two-dimensional multiple-band metal near the Lifshitz transition
• Theoretical study of spin-fluctuation-mediated superconductivity in two-dimensional Hubbard models with an incipient flat band
• Interplay between orbital-quantization effects and the Fulde-Ferrell-Larkin-Ovchinnikov instability in multiple-band layered superconductors
• Robust $s_{\pm }$-wave pairing in a bilayer two-orbital model of pressurized La${}_3$Ni${}_2$O${}_7$ without the $\gamma$ Fermi surface
• Particle-Hole Transformation in Strongly-Doped Iron-Based Superconductors
• Hidden Ladder in SrMoO${}_3$/SrTiO${}_3$ Superlattices: Experiments and Theoretical Calculations
• Superconductivity in the bilayer Hubbard model: Are two Fermi surfaces better than one?