Journal Article

PreJuSER-16383

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Magnetically driven superconductivity in CeCu2Si2

Stockert, O. ; Arndt, J. ; Faulhaber, E. ; Geibel, C. ; Jeevan, H. S. ; Kirchner, S. ; Loewenhaupt, M. ; Schmalzl, K.FZJ* ; Schmidt, W.FZJ* ; Si, Q. ; Steglich, F.

2011
Nature Publishing Group Basingstoke

This record in other databases:  

Please use a persistent id in citations: doi:10.1038/nphys1852

Abstract: The origin of unconventional superconductivity, including high-temperature and heavy-fermion superconductivity, is still a matter of controversy. Spin excitations instead of phonons are thought to be responsible for the formation of Cooper pairs. Using inelastic neutron scattering, we present the first in-depth study of the magnetic excitation spectrum in momentum and energy space in the superconducting and the normal states of CeCu2Si2. A clear spin excitation gap is observed in the superconducting state. We determine a lowering of the magnetic exchange energy in the superconducting state, in an amount considerably larger than the superconducting condensation energy. Our findings identify the antiferromagnetic excitations as the main driving force for superconducting pairing in this prototypical heavy-fermion compound located near an antiferromagnetic quantum critical point.

Keyword(s): J

Note: We greatly acknowledge helpful discussions with A. Chubukov, P. Coleman, T. Dahm, I. Eremin, B. Fak, A. Hiess, D. Scalapino and P. Thalmeier. This work was supported by the Deutsche Forschungsgemeinschaft through Forschergruppe 960 'Quantum phase transitions', as well as by the NSF Grant No. DMR-1006985 and the Robert A. Welch Foundation Grant No. C-1411.

---

Contributing Institute(s):

1. Streumethoden (PGI-4)
2. Streumethoden (JCNS-2)
3. Jülich-Aachen Research Alliance - Fundamentals of Future Information Technology (JARA-FIT)

Research Program(s):

1. Grundlagen für zukünftige Informationstechnologien (P42)
2. Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) (P55)

Appears in the scientific report 2011

---