Possible Evidence for Berezinskii–Kosterlitz–Thouless Transition in Ba(Fe<sub>0.914</sub>Co<sub>0.086</sub>)<sub>2</sub>As<sub>2</sub> Crystals
Wen-He Jiao,
Xiao-Feng Xu,
Hao Jiang,
Zhu-An Xu,
Qing-Hu Chen,
Guang-Han Cao
Affiliations
Wen-He Jiao
Interdisciplinary Center for Quantum Information, Zhejiang Province Key Laboratory of Quantum Technology and Devices, Department of Physics, Zhejiang University, Hangzhou 310027, China
Xiao-Feng Xu
Department of Applied Physics, Zhejiang University of Technology, Hangzhou 310023, China
Hao Jiang
School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, China
Zhu-An Xu
Interdisciplinary Center for Quantum Information, Zhejiang Province Key Laboratory of Quantum Technology and Devices, Department of Physics, Zhejiang University, Hangzhou 310027, China
Qing-Hu Chen
Interdisciplinary Center for Quantum Information, Zhejiang Province Key Laboratory of Quantum Technology and Devices, Department of Physics, Zhejiang University, Hangzhou 310027, China
Guang-Han Cao
Interdisciplinary Center for Quantum Information, Zhejiang Province Key Laboratory of Quantum Technology and Devices, Department of Physics, Zhejiang University, Hangzhou 310027, China
In this study, we measure the in-plane transport properties of high-quality Ba(Fe0.914Co0.086)2As2 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.
