Vortex-Nernst and Diamagnetism in Iron-based Superconductor Fe<sub>1+y</sub>Te<sub>1-x</sub>Se<sub>x</sub>

ORAL

Abstract

Nernst effect and torque magnetometry experiments have provided direct evidence for phase-coherence scenario in an iron-based superconductor Fe1+yTe1-xSex. The Nernst experiment, which measures the transverse electric field when applying a longitudinal temperature gradient and a perpendicular magnetic field, can detect vorticity with high sensitivity. Fe1+yTe1-xSex with different iron concentration has distinctly different critical temperature Tc, while their vortex-Nernst signal eN extends to a higher temperature Tonset and remains robust to fields of 13T. The fluctuation diamagnetic signal resolved by high-resolution torque magnetometry also onsets at temperature higher than Tc, and it scales similarly with the vortex-Nernst signal for the same sample. The results support the transition at Tc is caused by the loss of phase-rigidity of Cooper pairs.

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Presenters

  • Dechen Zhang

    • University of Michigan

Authors

  • Dechen Zhang

    • University of Michigan

  • Lu Chen

    • University of Michigan

  • Ziji Xiang

    • University of Michigan

  • Jiaxin Yin

    • Princeton University
    • Laboratory for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University
    • Department of Physics, Princeton University

  • Kuan-Wen Chen

    • University of Michigan

  • Guoxin Zheng

    • University of Michigan

  • Genda Gu

    • Brookhaven National Laboratory
    • Brookhaven National Laboratories
    • Brookhaven national lab
    • Brookhaven National Labs
    • Condensed Matter Physics and Materials Science Department
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • CMPMS, Brookhaven National Laboratory
    • Brookhaven National Lab
    • COndensed Matter Physics and Materials Science Department, Brookhaven National Laboratory

  • Lu Li

    • University of Michigan