Measurement of the current-phase relation in superconductor-topological insulator-superconductor Josephson junctions

ORAL

Abstract

The spin-helical topological surface states (TSS) of topological insulators in proximity with an s-wave superconductor are predicted to demonstrate signatures of topological superconductivity and host Majorana fermions. Here, we report highly skewed current-phase relation (CPR) in gate-tunable Josephson junctions made from topological insulator BiSbTeSe2 with superconducting Nb electrodes. Our observations provide strong evidences for the existence of low-energy states and the ballistic transport in the TI-based junctions. We also investigate the gate dependence of the CPR, where we observe that close to the Dirac point the transport becomes more diffusive, most likely due to the presence of electron/hole puddles.

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Presenters

  • Morteza Kayyalha

    Purdue University

Authors

  • Morteza Kayyalha

    Purdue University

  • Aleksandr Kazakov

    Department of Physics and Astronomy, Purdue University, Purdue University

  • I. Miotkowski

    Purdue University, Physics, Purdue Univ., Department of Physics and Astronomy, Purdue University

  • Sergei Khlebnikov

    Purdue University

  • Leonid Rokhinson

    Department of Physics and Astronomy, Purdue University, Purdue University

  • Yong Chen

    Purdue University, Department of Physics and Astronomy & ECE, Purdue university