Possible Evidence for Berezinskii-Kosterlitz-Thouless Transition in Ba(Fe0.914Co0.086)2As2 Crystals

In this study, we measure the in-plane transport properties of high-quality Ba(Fe0.914Co0.086)(2)As-2 single crystals. Signatures of vortex unbinding Berezinskii-Kosterlitz-Thouless (BKT) transition are shown from both the conventional approach and the Fisher-Fisher-Huse dynamic scaling analysis, in which a characteristic Nelson-Kosterlitz jump is demonstrated. We also observe a non-Hall transverse signal exactly at the superconducting transition, which is explained in terms of guided motion of unbound vortices.

Automated summary

The study demonstrates the presence of BKT transition and Nelson-Kosterlitz jump in high-quality Ba(Fe0.914Co0.086)(2)As-2 single crystals, along with a non-Hall transverse signal exactly at the superconducting transition, which is likely attributed to the guided motion of unbound vortices.