corner
corner
APS » Journals » Phys. Rev. Lett. » Volume 103 » Issue 6
< Previous Article | Next Article >

Phys. Rev. Lett. 103, 067008 (2009) [4 pages]

Spin Gap and Resonance at the Nesting Wave Vector in Superconducting FeSe0.4Te0.6

Download: PDF (540 kB) Buy this article Export: BibTeX or EndNote (RIS)

Yiming Qiu1,2, Wei Bao3,*, Y. Zhao4, Collin Broholm4,1, V. Stanev4, Z. Tesanovic4, Y. C. Gasparovic1,2, S. Chang1, Jin Hu5, Bin Qian5, Minghu Fang5,6, and Zhiqiang Mao5
1NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
2Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
3Department of Physics, Renmin University of China, Beijing 100872, China
4Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218 USA
5Department of Physics, Tulane University, New Orleans, Louisiana 70118 USA
6Department of Physics, Zhejiang University, Hangzhou 310027, China

Received 12 May 2009; published 7 August 2009

Neutron scattering is used to probe magnetic excitations in FeSe0.4Te0.6 (Tc=14  K). Low energy spin fluctuations are found with a characteristic wave vector (1/21/2L) that corresponds to Fermi surface nesting and differs from Qm=(δ01/2) for magnetic ordering in Fe1+yTe. A spin resonance with ℏΩ0=6.51(4)  meV≈5.3kBTc and ℏΓ=1.25(5)  meV develops in the superconducting state from a normal state continuum. We show that the resonance is consistent with a bound state associated with s± superconductivity and imperfect quasi-2D Fermi surface nesting.

© 2009 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevLett.103.067008
DOI:
10.1103/PhysRevLett.103.067008
PACS:
74.70.−b, 74.20.Mn, 74.25.Ha, 78.70.Nx

*wbao@ruc.edu.cn

 
< Previous Article | Next Article >