Unconventional pairing originating from disconnected Fermi surfaces in the iron-based superconductor

2009 ◽  
Vol 469 (9-12) ◽  
pp. 635-639 ◽  
Author(s):  
Kazuhiko Kuroki ◽  
Hideo Aoki
Keyword(s):  
Fermi Surfaces ◽  
Iron Based

scholarly journals Particle–Hole Transformation in Strongly-Doped Iron-Based Superconductors

Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 396
Author(s):  
Jose Rodriguez
Keyword(s):  
Brillouin Zone ◽  
Single Layer ◽  
Local Moment ◽  
Hole Doping ◽  
Cooper Pairs ◽  
Fermi Surfaces ◽  
Iron Based ◽  
Magnetic Resonances ◽  
Layer Iron ◽  
Electron Pocket

An exact particle–hole transformation is discovered in a local-moment model for a single layer of heavily electron-doped FeSe. The model harbors hidden magnetic order between the iron d x z and d y z orbitals at the wavenumber ( π , π ) . It potentially is tied to the magnetic resonances about the very same Néel ordering vector that have been recently discovered in intercalated FeSe. Upon electron doping, the local-moment model successfully accounts for the electron-pocket Fermi surfaces observed experimentally at the corner of the two-iron Brillouin zone in electron-doped FeSe, as well as for isotropic Cooper pairs. Application of the particle–hole transformation predicts a surface-layer iron-based superconductor at strong hole doping that exhibits high T c, and that shows hole-type Fermi-surface pockets at the center of the two-iron Brillouin zone.

scholarly journals Unconventional pairing originating from disconnected Fermi surfaces in the iron-based superconductor

2009 ◽  
Vol 11 (2) ◽  
pp. 025017 ◽  
Author(s):  
Kazuhiko Kuroki ◽  
Seiichiro Onari ◽  
Ryotaro Arita ◽  
Hidetomo Usui ◽  
Yukio Tanaka ◽  
...  
Keyword(s):  
Fermi Surfaces ◽  
Iron Based

scholarly journals Pressure-induced reconstitution of Fermi surfaces and spin fluctuations in S-substituted FeSe

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Kuwayama ◽  
K. Matsuura ◽  
J. Gouchi ◽  
Y. Yamakawa ◽  
Y. Mizukami ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Density Of States ◽  
Spin Fluctuations ◽  
Fermi Surfaces ◽  
Lifshitz Transition ◽  
Different Types ◽  
Iron Based ◽  
Nuclear Magnetic

AbstractFeSe is a unique high-$$T_c$$ T c iron-based superconductor in which nematicity, superconductivity, and magnetism are entangled with each other in the P-T phase diagram. We performed $$^{77}$$ 77 Se-nuclear magnetic resonance measurements under pressures of up to 3.9 GPa on 12% S-substituted FeSe, in which the complex overlap between the nematicity and magnetism are resolved. A pressure-induced Lifshitz transition was observed at 1.0 GPa as an anomaly of the density of states and as double superconducting (SC) domes accompanied by different types of antiferromagnetic (AF) fluctuations. The low-$$T_{\mathrm{c}}$$ T c SC dome below 1 GPa is accompanied by strong AF fluctuations, whereas the high-$$T_{\mathrm{c}}$$ T c SC dome develops above 1 GPa, where AF fluctuations are fairly weak. These results suggest the importance of the $$d_{xy}$$ d xy orbital and its intra-orbital coupling for the high-$$T_{\mathrm{c}}$$ T c superconductivity.

scholarly journals The 3-Dimensional Fermi Liquid Description for the Iron-Based Superconductors

2017 ◽  
Vol 190 (1-2) ◽  
pp. 45-66 ◽  
Author(s):  
Setsuo Misawa
Keyword(s):  
Fermi Liquid ◽  
Fermi Liquids ◽  
Electronic Specific Heat ◽  
Superconducting Transition ◽  
Iron Based Superconductors ◽  
Fermi Surfaces ◽  
3 Dimensional ◽  
Quasiparticle Energy ◽  
Iron Based ◽  
Specific Heat Coefficient

Abstract The quasiparticles in the normal state of iron-based superconductors have been shown to behave universally as a 3-dimensional Fermi liquid. Because of interactions and the presence of sharp Fermi surfaces, the quasiparticle energy contains, as a function of the momentum $$\varvec{p}$$ p , a term of the form $$( p - p_0)^3 \ln {( |p-p_0|/p_0)} $$ ( p - p 0 ) 3 ln ( | p - p 0 | / p 0 ) , where $$p = | \varvec{p} |$$ p = | p | and $$p_0$$ p 0 is the Fermi momentum. The electronic specific heat coefficient, magnetic susceptibility (Knight shift), electrical resistivity, Hall coefficient and thermoelectric power divided by temperature follow, as functions of temperature T, the logarithmic formula $$a-b T^2 \ln {(T/T^*)}$$ a - b T 2 ln ( T / T ∗ ) , $$a, \, b$$ a , b and $$T^*$$ T ∗ being constant; these formulae have been shown to explain the observed data for all iron-based superconductors. It is shown that the concept of non-Fermi liquids or anomalous metals which appears in the literature is not needed for descriptions of the present systems. When the superconducting transition temperature $$T_{\mathrm {C}}$$ T C and the b / a value for the resistivity are plotted as functions of the doping content x, there appear various characteristic diagrams in which regions of positive correlation and those of negative correlation between $$T_{\mathrm {C}}$$ T C and b / a are interconnected; from these diagrams, we may make speculations about the types of superconductivity and the crossover between them.

Unconventional Superconductivity Originating from Disconnected Fermi Surfaces in the Iron-Based Oxypnictide

2008 ◽  
Vol 77 (Suppl.C) ◽  
pp. 96-98 ◽  
Author(s):  
Kazuhiko Kuroki ◽  
Seiichiro Onari ◽  
Ryotaro Arita ◽  
Hidetomo Usui ◽  
Yukio Tanaka ◽  
...  
Keyword(s):  
Unconventional Superconductivity ◽  
Fermi Surfaces ◽  
Iron Based

Magnetic Circular X-Ray Dichroism at the Ce LII,IIIEdges in Ferromagnetic Iron Based Intei metallic

1997 ◽  
Vol 7 (C2) ◽  
pp. C2-439-C2-440
Author(s):  
O. Isnard ◽  
S. Miraglia ◽  
Ch. Giorgetti ◽  
F. Baudelet ◽  
E. Dartyge ◽  
...  
Keyword(s):  
X Ray ◽  
Iron Based ◽  
Ferromagnetic Iron

An Iron-Based Catalyst Enables The Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction

2020 ◽  
Author(s):  
Chet Tyrol ◽  
Nang Yone ◽  
Connor Gallin ◽  
Jeffery Byers
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Radical Intermediates ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Boronic Esters ◽  
Carbon Centered Radical ◽  
Iron Based ◽  
High Yields

By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura crosscoupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates.

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