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AC Power Dependence of Shapiro Steps in YBCO Josephson Junctions: Exploring the Metal-Insulator Transition

ORAL

Abstract

The helium ion Josephson junction fabrication process allows one to tune the barrier properties through the metal-insulator transition (MIT) by varying the irradiation dosage. This enabled us to measure and compare the effect of AC power dependence on the step heights for YBCO Josephson junctions with metallic and insulating barriers. Microwave radiation at 18 GHz was applied through a dipole antenna to induce Shapiro steps in the DC current-voltage characteristics, and we measured the 0th, through 4th order step heights as a function of power. The step heights exhibited Bessel function-like dependencies, indicative of current source-like behavior. Changes in Shapiro step oscillation period were observed as we passed through the MIT. In this presentation, we will analyze and compare the variations in oscillations and present a model of how the current-phase relationship

Presenters

  • Adhilsha Parachikunnumal

    University of California, Riverside

Authors

  • Adhilsha Parachikunnumal

    University of California, Riverside

  • Nirjhar Sarkar

    University of California, San Diego

  • sreekar vattipalli

    University of California, Riverside

  • Jay LeFebvre

    UCR, University of California, Riveside, University of California Riverside

  • Shane A Cybart

    UCR, University of California, Riverside