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arXiv · 0907.3875

Contrasting Spin Dynamics Between Underdoped and Overdoped Ba(Fe[1-x]Co[x])2As2

F. L. Ning·K. Ahilan·T. Imai·A. S. Sefat·M. A. McGuire·B. C. Sales·D. Mandrus·P. Cheng·B. Shen·H. -H Wen
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Abstract

We report the first NMR investigation of spin dynamics in the overdoped non-superconducting regime of Ba(Fe[1-x]Co[x])2As2 up to x =0.26. We demonstrate that the absence of inter-band transitions with large momentum transfer Q(AF) ~ (pi, 0) between the hole and electron Fermi surfaces results in complete suppression of antiferromagnetic spin fluctuations for x > 0.15. Our experimental results provide direct evidence for a correlation between Tc and the strength of Q(AF) antiferromagnetic spin fluctuations.

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F. L. Ning, K. Ahilan, T. Imai, A. S. Sefat, M. A. McGuire, B. C. Sales, D. Mandrus, P. Cheng, B. Shen, H. -H Wen. 2010-01-09. Contrasting Spin Dynamics Between Underdoped and Overdoped Ba(Fe[1-x]Co[x])2As2. https://doi.org/10.1103/physrevlett.104.037001

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