TY - JOUR AU - Stockert, O. AU - Arndt, J. AU - Faulhaber, E. AU - Geibel, C. AU - Jeevan, H. S. AU - Kirchner, S. AU - Loewenhaupt, M. AU - Schmalzl, K. AU - Schmidt, W. AU - Si, Q. AU - Steglich, F. TI - Magnetically driven superconductivity in CeCu2Si2 JO - Nature physics VL - 7 SN - 1745-2473 CY - Basingstoke PB - Nature Publishing Group M1 - PreJuSER-16383 SP - 119 - 124 PY - 2011 N1 - 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. AB - 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. KW - J (WoSType) LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000286807000012 DO - DOI:10.1038/nphys1852 UR - https://juser.fz-juelich.de/record/16383 ER -