Magnetic Bound States in Dimerized Quantum Spin Systems
  Magnetic bound states are a general phenomenon in low dimensional antiferromagnets with gapped singlet states. Using Raman scattering on three compounds as dedicated examples we show how exchange topology, dimensionality, defects and thermal fluctuations influence the properties and the spectral weight of these states. 
P. Lemmens, M. Fischer, M. Grove, G. Els, G. G\"untherodt, M. Weiden,   C. Geibel, F. Steglich