Cuprate films offer a unique opportunity to observe vortex tunneling effects, due to their unusually low superfluid density and short coherence length. Here, we measure the magnetoresistance (\textit{MR}) due to vortex motion of a long meander line of a superconducting film made of underdoped YBa2Cu3O7−δ. At low temperatures (\textit{T}), the \textit{MR} shows a significant deviation from Arrhenius activation. The data is consistent with two dimensional Variable Range Hopping (VRH) of single vortices, i.e. MR∝exp[−(T0/T)1/3]. The VRH temperature scale T0 depends on the vortex tunneling rates between pinning sites. We discuss its magnitude with respect to estimated parameters of the meander thin film.
@article{arxiv.0707.2484,
title = {Quantum vortex tunneling in $YBa_2Cu_3O_{7-\delta}$ thin films},
author = {G. Koren and Y. Mor and A. Auerbach and E. Polturak},
journal= {arXiv preprint arXiv:0707.2484},
year = {2009}
}