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arXiv · 1109.5196

Friedel-like Oscillations from Interstitial Iron in Superconducting Fe1+yTe0.62Se0.38

V. Thampy·J. Kang·J. A. Rodriguez-Rivera·W. Bao·A. T. Savici·J. Hu·T. J. Liu·B. Qian·D. Fobes·Z. Q. Mao·C. B. Fu·W. C. Chen·Q. Ye·R. W. Erwin·T. R. Gentile·Z. Tesanovic·C. Broholm
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Abstract

Using polarized and unpolarized neutron scattering we show that interstitial Fe in superconducting Fe_{1+y}Te_{1-x}Se_x induces a magnetic Friedel-like oscillation that diffracts at Q_(in-plane)=(1/2,0) and involves >50 neighboring Fe sites. The interstitial >2 mu_B moment is surrounded by compensating ferromagnetic four spin clusters that may seed double stripe ordering in Fe_{1+y}Te. A semi-metallic 5-band model with (1/2,1/2) Fermi surface nesting and four fold symmetric super-exchange between interstitial Fe and two in-plane nearest neighbors largely accounts for the observed diffraction.

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V. Thampy, J. Kang, J. A. Rodriguez-Rivera, W. Bao, A. T. Savici, J. Hu, T. J. Liu, B. Qian, D. Fobes, Z. Q. Mao, C. B. Fu, W. C. Chen, Q. Ye, R. W. Erwin, T. R. Gentile, Z. Tesanovic, C. Broholm. 2011-09-23. Friedel-like Oscillations from Interstitial Iron in Superconducting Fe1+yTe0.62Se0.38. https://doi.org/10.1103/physrevlett.108.107002

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