Band shifts are systematically observed in pnictides using de Hass-van Alphen and ARPES techniques. Most interesting, such shifts result to be band-sensitive, so that hole-like bands are shifted downwards while electron-like ones are shifted upwards. In this contribution we present a comprehensive explanation for the origin of such band shifts. Using a four band Eliashberg analysis, we show that they are a natural consequence of the multiband character of these systems and of the strong particle-hole asymmetry of the bands. We also show that the relative sign of such shifts provides a direct experimental evidence of a dominant interband scattering. A quantitative analysis in LaFePO yields a spin-mediated interband coupling of the order V approximate to 0.46 eV which corresponds to a mass enhancement Z approximate to 1.5. (C) 2009 Elsevier B.V. All rights reserved.
Fermi surface shrinking, band shifts and interband coupling in iron-based pnictides / Cappelluti, E.; Ortenzi, L.; Benfatto, L.; Pietronero, Luciano. - In: PHYSICA. C, SUPERCONDUCTIVITY. - ISSN 0921-4534. - 470:1(2010), pp. S508-S510. (Intervento presentato al convegno 9th International Conference on Materials and Mechanisms of Superconductivity tenutosi a Tokyo, JAPAN nel SEP 07-12, 2009) [10.1016/j.physc.2009.10.016].
Fermi surface shrinking, band shifts and interband coupling in iron-based pnictides
L. Benfatto;PIETRONERO, Luciano
2010
Abstract
Band shifts are systematically observed in pnictides using de Hass-van Alphen and ARPES techniques. Most interesting, such shifts result to be band-sensitive, so that hole-like bands are shifted downwards while electron-like ones are shifted upwards. In this contribution we present a comprehensive explanation for the origin of such band shifts. Using a four band Eliashberg analysis, we show that they are a natural consequence of the multiband character of these systems and of the strong particle-hole asymmetry of the bands. We also show that the relative sign of such shifts provides a direct experimental evidence of a dominant interband scattering. A quantitative analysis in LaFePO yields a spin-mediated interband coupling of the order V approximate to 0.46 eV which corresponds to a mass enhancement Z approximate to 1.5. (C) 2009 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
