Nature457, 569-572 (29 January 2009) | doi:10.1038/nature07714; Received 11 September 2008; Accepted 2 December 2008
(, ) electronic order in iron arsenide superconductors
V. B. Zabolotnyy1, D. S. Inosov1,2, D. V. Evtushinsky1, A. Koitzsch1, A. A. Kordyuk1,3, G. L. Sun2, J. T. Park2, D. Haug2, V. Hinkov2, A. V. Boris2,4, C. T. Lin2, M. Knupfer1, A. N. Yaresko2, B. Büchner1, A. Varykhalov5, R. Follath5 & S. V. Borisenko1
Institute for Solid State Research, IFW-Dresden, PO Box 270116, 01171 Dresden, Germany
Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
Institute of Metal Physics of National Academy of Sciences of Ukraine, 03142 Kyiv, Ukraine
Department of Physics, Loughborough University, Loughborough, LE11 3TU, UK
Elektronenspeicherring BESSY II, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
Correspondence to: S. V. Borisenko1 Correspondence and requests for materials should be addressed to S.V.B. (Email: firstname.lastname@example.org).
The distribution of valence electrons in metals usually follows the symmetry of the underlying ionic lattice. Modulations of this distribution often occur when those electrons are not stable with respect to a new electronic order, such as spin or charge density waves. Electron density waves have been observed in many families of superconductors1, 2, 3, and are often considered to be essential for superconductivity to exist4. Recent measurements5, 6, 7, 8, 9 seem to show that the properties of the iron pnictides10, 11 are in good agreement with band structure calculations that do not include additional ordering, implying no relation between density waves and superconductivity in these materials12, 13, 14, 15. Here we report that the electronic structure of Ba1-xKxFe2As2 is in sharp disagreement with those band structure calculations12, 13, 14, 15, and instead reveals a reconstruction characterized by a (, ) wavevector. This electronic order coexists with superconductivity and persists up to room temperature (300 K).