The 63Cu and 17O nuclear spin-lattice relaxation rates in YBa2Cu4O8 have been measured in the temperature and magnetic field ranges of 1.4-270 K and 4.0-11 T, respectively. In the mixed state, 1/T1 for both 63Cu and 17O are enhanced by the magnetic field. Most strikingly, in a high field of 11 T, 63(1/T1) and 17(1/T1) decrease in proportion to the temperature, T, below T=15 K and T=10 K, respectively. The magnetic-field dependence of 1/T1 is shown to be dominated by spin diffusion to the vortex cores, implying that the electronic state in the cores is characterized by the T1T=const. law. This result indicates that the electronic state in the vortex cores is described in terms of the Fermi-liquid picture, in sharp contrast to the unusual properties above Tc.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering