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arXiv · 1012.4271

Behavior of vortices near twin boundaries in underdoped $Ba(Fe_{1-x}Co_{x})_{2}As_{2}$

B. Kalisky·J. R. Kirtley·J. G. Analytis·J. -H. Chu·I. R. Fisher·K. A. Moler
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Abstract

We use scanning SQUID microscopy to investigate the behavior of vortices in the presence of twin boundaries in the pnictide superconductor Ba(Fe1-xCox)2As2. We show that the vortices avoid pinning on twin boundaries. Individual vortices move in a preferential way when manipulated with the SQUID: they tend to not cross a twin boundary, but rather to move parallel to it. This behavior can be explained by the observation of enhanced superfluid density on twin boundaries in Ba(Fe1-xCox)2As2. The observed repulsion from twin boundaries may be a mechanism for enhanced critical currents observed in twinned samples in pnictides and other superconductors.

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B. Kalisky, J. R. Kirtley, J. G. Analytis, J. -H. Chu, I. R. Fisher, K. A. Moler. 2010-12-20. Behavior of vortices near twin boundaries in underdoped $Ba(Fe_{1-x}Co_{x})_{2}As_{2}$. https://doi.org/10.1103/physrevb.83.064511

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