Quantum tunneling of massive flux lines in a high-T-c superconductor

We have investigated the quantum tunneling of damped flux lines of finite m ass at T = 0 by extending our previous study of tunneling around T-0, the t ransition temperature. In the case of a cubic pinning potential, considered here, the action could be evaluated in a closed form for a flux line of fi nite length. The tunneling rate reaches a finite limit at T = 0, although i t is temperature dependent and exhibits a 1/T variation near T-0.