Local quasiparticle density of states of superconducting SmFeAsO(1-x)F(x) single crystals: evidence for spin-mediated pairing.
Phys Rev Lett
; 105(16): 167005, 2010 Oct 15.
Article
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| MEDLINE
| ID: mdl-21231000
ABSTRACT
We probe the local quasiparticles density of states in micron-sized SmFeAsO(1-x)F(x) single crystals by means of scanning tunnelling spectroscopy. Spectral features resemble those of cuprates, particularly a dip-hump-like structure developed at energies larger than the gap that can be ascribed to the coupling of quasiparticles to a collective mode, quite likely a resonant spin mode. The energy of the collective mode revealed in our study decreases when the pairing strength increases. Our findings support spin-fluctuation-mediated pairing in pnictides.