Quantum vortex tunneling in $YBa_2Cu_3O_{7-δ}$ thin films

G. Koren; Y. Mor; A. Auerbach; E. Polturak

doi:10.1103/physrevb.76.134516

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arXiv · 0707.2484

Quantum vortex tunneling in $YBa_2Cu_3O_{7-δ}$ thin films

G. Koren·Y. Mor·A. Auerbach·E. Polturak

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Abstract

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 $YBa_2Cu_3O_{7-δ}$. 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. $MR\propto exp[-(T_0/T)^{1/3}]$. The VRH temperature scale $T_0$ depends on the vortex tunneling rates between pinning sites. We discuss its magnitude with respect to estimated parameters of the meander thin film.

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G. Koren, Y. Mor, A. Auerbach, E. Polturak. 2007-07-17. Quantum vortex tunneling in $YBa_2Cu_3O_{7-δ}$ thin films. https://doi.org/10.1103/physrevb.76.134516

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