Magnetic fluctuations and superconductivity in Fe pnictides probed by electron spin resonance

N. Pascher; J. Deisenhofer; H. -A. Krug von Nidda; M. Hemmida; H. S. Jeevan; P. Gegenwart; A. Loidl

doi:10.1103/PhysRevB.82.054525

Magnetic fluctuations and superconductivity in Fe pnictides probed by electron spin resonance

Superconductivity 2010-09-02 v2 Strongly Correlated Electrons

Authors: N. Pascher , J. Deisenhofer , H. -A. Krug von Nidda , M. Hemmida , H. S. Jeevan , P. Gegenwart , A. Loidl

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Abstract

The electron spin resonance absorption spectrum of Eu^{2+} ions serves as a probe of the normal and superconducting state in Eu_{0.5}K_{0.5}Fe_2As_2. The spin-lattice relaxation rate 1/T_1^{\rm ESR} obtained from the ESR linewidth exhibits a Korringa-like linear increase with temperature above T_C evidencing a normal Fermi-liquid behavior. Below 45 K deviations from the Korringa-law occur which are ascribed to enhanced magnetic fluctuations within the FeAs layers upon approaching the superconducting transition. Below T_C the spin-lattice relaxation rate 1/T_1^{\rm ESR} follows a T^{1.5}-behavior without the appearance of a coherence peak.

Keywords

electron spin resonance iron pnictides superconductivity magnetic fluctuations spin-lattice relaxation Fermi liquid Korringa law

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@article{arxiv.1001.1302,
  title  = {Magnetic fluctuations and superconductivity in Fe pnictides probed by electron spin resonance},
  author = {N. Pascher and J. Deisenhofer and H. -A. Krug von Nidda and M. Hemmida and H. S. Jeevan and P. Gegenwart and A. Loidl},
  journal= {arXiv preprint arXiv:1001.1302},
  year   = {2010}
}

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5 pages, 5 figures

Magnetic fluctuations and superconductivity in Fe pnictides probed by electron spin resonance

Abstract

Keywords

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