Toward control and manipulation of superconducting vortex lattices from nano to mesoscales

ORAL

Abstract

Vortices in unconventional superconductors can support fundamentally new electronic excitations and act as a basic building block of quantum computing architecture. Finding new pathways to control the morphology and dynamics of vortex lattices will be critical to the development of emerging quantum technologies. In this talk, we will discuss the following things. First, we observed that the twin boundary in the FeSe superconductor traps a relatively high density of vortices and acts as a barrier that aligns the vortices on the terrace parallel to the twin boundary. The alignment effect causes various phases of vortex lattice structures such as rectangular and one-dimensional vortex lattices. By comparing theoretical predictions with experimental results, we have inferred the characteristic energetics of the interaction between superconducting and nematic order parameters, and we have predicted the existence of geometric size effects on the symmetry of the vortex lattice subject to confinement by the crossing twin boundaries. Second, we found that the vortex cores are extended as progressively increases current density using STM. Furthermore, we manipulated the local distribution of vortices under extreme conditions. We will discuss candidates for driving forces. These results give us valuable information to understand the properties of vortex-bound state under driving force, and the detailed mechanism of vortex manipulation. Altogether we suggest that precise control over the high tunneling current can translate into an effective vortex manipulation approach without destruction of the superconducting state, with the possibility of one or several driving mechanisms depending on specific conditions. Our results give valuable hints to the understanding of vortex manipulation in STM geometry toward quantitative nanoscale probes of vortex dynamics and a platform to explore vortex manipulation in the context of topological quantum computing.

*This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences, and Engineering Division. Scanning tunneling microscopy was performed at the Center for Nanophase Materials Sciences (CNMS), which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory.

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Presenters

  • Sang Yong Song

    • Oak Ridge National Laboratory
    • Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

Authors

  • Sang Yong Song

    • Oak Ridge National Laboratory
    • Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

  • Jiaqiang Yan

    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

  • Wonhee Ko

    • University of Tennessee, Knoxville
    • Department of Physics and Astronomy, University of Tennessee at Knoxville, Knoxville TN 37996, USA
    • University of Tennessee

  • Eugene F Dumitrescu

    • Oak Ridge National Laboratory
    • Computational Science and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

  • Gábor Halász

    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory

  • Chengyun Hua

    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory

  • Hans Fangohr

    • Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, UK
    • Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany

  • Benjamin J Lawrie

    • Oak Ridge National Lab
    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory

  • Petro Maksymovych

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA