Coherence–incoherence crossover in the normal state of iron oxypnictides and importance of Hund's rule coupling
By K. Haule, Gabriel Kotliar. 2008
376 citations recorded by the source corpus.
A new class of high-temperature superconductors based on iron and arsenic was recently discovered (Kamihara et al 2008 J. Am. Chem. Soc. 130 3296), with the superconducting transition temperature as high as 55 K (Ren et al 2008 Chin. Phys. Lett. 25 2215). Here we show, using microscopic theory, that the normal state of the iron pnictides at high temperatures is highly anomalous, displaying a very enhanced magnetic susceptibility and a linear temperature dependence of the resistivity. Below a coherence scale T*, the resistivity sharply drops and susceptibility crosses over to Pauli-like temperature dependence. Remarkably, the coherence–incoherence crossover temperature is a very strong function of the strength of Hund's rule coupling JHund. On the basis of the normal state properties, we estimate JHund to be ∼0.35 eV. In the atomic limit, this value of JHund leads to the critical ratio of the exchange constants J1/J2∼2. While normal state incoherence is common to all strongly correlated superconductors, the mechanism for emergence of the incoherent state in iron oxypnictides is unique due to its multiorbital electronic structure.
Subfields: Electronic, Optical and Magnetic Materials
View Paper: https://www.semanticscholar.org/paper/a60c72a29121b9916514df74bd3cd6c1f93075a1
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In Electronic, Optical and Magnetic Materials
Citations in the corpus
- Kinetic frustration and the nature of the magnetic and paramagnetic states in iron pnictides and iron chalcogenides. (2011, background): “The iron pnictides are Hund’s metals [4], where the interaction between the electrons is not strong enough to fully localize them, but it significantly slows them down, so that the low energy quasiparticles have much enhanced mass.”
- Magnetism and its microscopic origin in iron-based high-temperature superconductors (2012, background): “In the “physical region” the ratio JH/U is approximately 1/4 [98], as in other estimations [96], highlighting the importance of JH in these materials that are sometimes referred to as Hund metals [103].”
- Angle-resolved photoemission studies of quantum materials (2020, neutral): “…(Dagotto, 2013; Dai, 2015; Dai et al., 2012; Davis and Lee, 2013; Fernandes and Chubukov, 2016; Fernandes et al., 2014; Georges et al., 2013; Haule and Kotliar, 2009; Si et al., 2016), superconducting pairing mechanism (Bang and Stewart, 2017; Chubukov, 2012; Hirschfeld et al., 2011;…”