Direct Observation of Superconducting Pair States in Atomic Resolution on Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta }$

ORAL

Abstract

Conventional Spectroscopic Imaging Scanning Tunneling Microscopy (SI-STM) utilizes metal tips which limits ones only to access the information of quasiparticles, not superconducting pairs. We report the first atomically resolved Scanning Josephson Tunneling Microscopy (SJTM) on Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta }$ (Bi-2212) using Bi-2212 tips which is formed \textit{in situ}. Conductance maps measured by Bi-2212 tips show clear Josephson $I$-$V$ characteristics which can be explained by considering Josephson phase diffusion due to thermal fluctuations. Zero Bias Conductance Peaks (ZBCPs) following Ambegaokar-Baratoff (AB) theory were directly measured by lock-in technique by which we can probe SC pairs directly. We will also present studies of Zn impurities on Bi-2212 using SJTM.

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Authors

  • Sang Hyun Joo

    • Seoul National University

  • Inhee Lee

    • Brookhaven National Laboratory

  • Chung Koo Kim

    • Brookhaven National Laboratory

  • Jung Hoon Yoo

    • Seoul National University

  • Min Seok Park

    • Seoul National University

  • Gyoung Seok Lee

    • Seoul National University

  • Jae-joon Kim

    • Seoul National University

  • Genda Gu

    • Brookhaven National Laboratory

  • Kyle McElroy

    • University of Colorado at Boulder, Boulder

  • Shin-ichi Uchida

    • University of Tokyo

  • J.C. Davis

    • Cornell University, Brookhaven National Laboratory

  • Jinho Lee

    • Seoul National University