Spin-lattice relaxation in the mixed state of the high-T-c cuprates: Electronic spin-flip scattering versus spin fluctuations - art. no. 214509

Recent experimental and theoretical studies have established that the spin- lattice relaxation rate 1/T-1 measured in nuclear magnetic resonance (NMR) experiments is a site-sensitive probe for-the electronic spectrum in the mi xed state of the high-T-c cuprates. While some groups suggested that 1/T-1 is solely determined by spin-flip scattering of BCS-like electrons, other g roups stressed the importance of antiferromagnetic spin-fluctuations. We sh ow that these two relaxation mechanisms give rise to a qualitatively differ ent temperature and frequency dependence of O-17 1/T-1. A comparison of our results with the experimental O-17 1/T-1 data provides support for a relax ation mechanism dominated by antiferromagnetic spin fluctuations.