J. Tejada et al., QUANTUM TUNNELING OF VORTICES IN THE TL2CABA2CU2O8 SUPERCONDUCTOR, Physical review. B, Condensed matter, 47(17), 1993, pp. 11552-11554
Magnetic-relaxation measurements of a T1-based high-T(c) superconducto
r show temperature-independent flux creep below 6 K. The effect is ana
lyzed in terms of the overdamped quantum diffusion of two-dimensional
vortices. Good agreement between theory and experiment is found.