Electronic correlations in the iron pnictides

By M. M. Qazilbash, J. Hamlin, R. Baumbach, Lijun Zhang, David J. Singh, M. Maple, D. Basov. 2009

311 citations recorded by the source corpus.

When electrons experience Coulomb repulsion, their kinetic energy becomes significantly reduced. This effect has now been measured in the pnictide superconductor LaFePO, and shows that correlations between electrons in these materials are just as strong as in some copper oxide and ruthenate superconductors. In correlated metals derived from Mott insulators, the motion of an electron is impeded by Coulomb repulsion due to other electrons. This phenomenon causes a substantial reduction in the electron’s kinetic energy, leading to remarkable experimental manifestations in optical spectroscopy1. The high-transition-temperature (Tc) superconducting cuprates are perhaps the most studied examples of such correlated metals. The occurrence of high-Tc superconductivity in the iron pnictides2,3,4 puts a spotlight on the relevance of correlation effects in these materials5. Here, we present an infrared and optical study on single crystals of the iron pnictide superconductor LaFePO. We find clear evidence of electronic correlations in metallic LaFePO with the kinetic energy of the electrons reduced to half of that predicted by band theory of nearly free electrons. We deduce that electronic many-body effects are important in the iron pnictides despite the absence of a Mott transition.

Subfields: Accounting, Electronic, Optical and Magnetic Materials, Strategy and Management

View Paper: https://www.semanticscholar.org/paper/169ae86561fa60156a2f317280eab6615d3712b2

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Accounting

1. E. Dagotto
2. Gabriel Kotliar
3. R. Greene
4. J. Paglione
5. K. Haule

In Electronic, Optical and Magnetic Materials

1. E. Dagotto
2. P. Dai
3. R. Averitt
4. Jiangping Hu
5. K. Haule
6. D. Basov
7. Gabriel Kotliar
8. D. Marel

In Strategy and Management

1. R. Greene
2. J. Paglione

Citations in the corpus

• High-temperature superconductivity in iron-based materials (2010, background): “Optical measurements on LaFePO have indicated that many-body effects are important, identifying this material as a moderately correlated metal and BaFe 2 As 2 as even more s”
• Colloquium: Graphene spectroscopy (2014, background): “4b. Redistribution of the optical weight is common to correlated electron systems (Basov et al., 2011; Millis, 2004; Qazilbash et al., 2009), and so the residual conductivity of graphene is suggestive of interaction effects.”
• Kinetic frustration and the nature of the magnetic and paramagnetic states in iron pnictides and iron chalcogenides. (2011, background): “1b we also show the mass enhancement extracted from optic”
• Magnetism and its microscopic origin in iron-based high-temperature superconductors (2012, background): “Additional insight is provided by optical conductivity experiments, since the ratio R between the experimentally measured kinetic energy and that of band-theory calculations can be measured and contrasted against other compounds [57].”
• Electrodynamics of correlated electron materials (2011, background): “This latter result is in accord with the notion that proximity to antiferromagnetic order does not appreciably reduce electronic kinetic energy of a conducting system (Qazilbash et al., 2009b).”
• Flat bands, strange metals and the Kondo effect (2023, unknown): “80–82) (Fig.”