Calculated NMR T-2 relaxation due to vortex vibrations in cuprate superconductors

Article

关键词: SPIN-LATTICE-RELAXATION;    MIXED-STATE;    FLUX LINES;    ECHO DECAY;    DYNAMICS;    FLUCTUATIONS;   

DOI  :  10.1103/PhysRevB.74.134516

来源: SCIE

【 摘 要 】

We calculate the rate of transverse relaxation arising from vortex motion in the mixed state of YBa2Cu3O7 with the static field applied along the c axis. The vortex dynamics are described by an overdamped Langevin equation with a harmonic elastic-free energy. We find that the variation of the relaxation with temperature, average magnetic field, and local field is consistent with experiments; however, the calculated time dependence is different from what has been measured and the value of the rates calculated is roughly two orders of magnitude slower than what is observed. Combined with the strong experimental evidence pointing to vortex motion as the dominant mechanism for T-2 relaxation, these results call into question a prior conclusion that vortex motion is not significant in T-1 measurements in the vortex state.

【 授权许可】

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