Tunable Josephson Junction Arrays in LaAlO<sub>3</sub>/KTaO<sub>3</sub>

ORAL

Abstract

Two-dimensional superconductivity at KTaO₃ (KTO) interfaces provides a platform for studying correlated electronic states in oxide materials with strong spin-orbit coupling and large dielectric response. Building on previous demonstrations of KTO-based Josephson junctions and superconducting quantum interference devices (SQUIDs)[1], we extend this platform to two-dimensional Josephson junction arrays (JJAs) patterned via conductive atomic force microscope (c-AFM) lithography and ultra-low voltage electron beam lithography (ULV-EBL). These networks enable exploration of collective quantum phenomena emerging from the interplay between superconducting phase coherence, magnetic frustration, and charging effects. We focus on vortex dynamics and search for the existence of a Bose metal phase in this system. The reconfigurability and electrostatic tunability of KTO make it an ideal platform for analog quantum simulation of correlated superconducting phases.

[1] M. Yu, et al., Phys. Rev. X 15, 011037 (2025)

*JL and PI acknowledge support from the National Science Foundation (DMR-2225888) and DARPA SynQuaNon (HR00112490317). C.B.E acknowledges funding by the Gordon and Betty Moore Foundation’s EPiQS Initiative (grant GBMF9065) and a Vannevar Bush Faculty Fellowship (ONR N00014-20-1-2844).

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Presenters

  • Ahmed Omran

    • University of Pittsburgh

Authors

  • Ahmed Omran

    • University of Pittsburgh

  • Jieun Kim

    • University of Wisconsin - Madison

  • Muqing Yu

    • University of Pittsburgh

  • Jiangfeng Yang

    • University of Wisconsin - Madison

  • Zhehao Dai

    • University of Pittsburgh
    • Department of Physics and Astronomy, University of Pittsburg

  • Pubudu Wijesinghe

    • University of Pittsburgh

  • Chang-Beom Eom

    • University of Wisconsin - Madison
    • University of Wisconsin-Madison

  • Patrick R Irvin

    • University of Pittsburgh

  • Jeremy Levy

    • University of Pittsburgh