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arXiv · 2504.10912

Superconducting quantum oscillations and anomalous negative magnetoresistance in a honeycomb nanopatterned oxide interface superconductor

Yishuai Wang·Siyuan Hong·Wenze Pan·Yi Zhou·Yanwu Xie
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Abstract

The extremely low superfluid density and unprecedented tunability of oxide interface superconductors provide an ideal platform for studying fluctuations in two-dimensional superconductors. In this work, we have fabricated a LaAlO3/KTaO3 interface superconductor patterned with a nanohoneycomb array of insulating islands. Little-Parks-like magnetoresistance oscillations have been observed, which are dictated by the superconducting flux quantum h/2e. Moreover, an anomalous negative magnetoresistance (ANMR) appears under a weak magnetic field, suggesting magnetic-field-enhanced superconductivity. By examining their dependences on temperature, measurement current, and electrical gating, we conclude that both phenomena are associated with superconducting order parameter: The h/2e oscillations provide direct evidence of Cooper pair transport; the ANMR is interpreted as a consequence of multiple connected narrow superconducting paths with strong fluctuations.

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Yishuai Wang, Siyuan Hong, Wenze Pan, Yi Zhou, Yanwu Xie. 2025-04-15. Superconducting quantum oscillations and anomalous negative magnetoresistance in a honeycomb nanopatterned oxide interface superconductor. https://doi.org/10.1103/physrevx.15.011006

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