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DOE OSTI · 2284061

Twisted cuprate van der Waals heterostructures with controlled Josephson coupling

Martini, Mickey·Lee, Yejin·Confalone, Tommaso·Shokri, Sanaz·Saggau, Christian N.·Wolf, Daniel·Gu, Genda·Watanabe, Kenji·Taniguchi, Takashi·Montemurro, Domenico·Vinokur, Valerii M.·Nielsch, Kornelius·Poccia, Nicola
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Abstract

Twisted van derWaals (vdW) heterostructures offer a unique platform for engineering the efficient Josephson coupling between cuprate thin crystals harboring the nodal superconducting order parameter. Preparing the vdW heterostructures-based Josephson junction comprising stacked cuprates requires maintaining an ordered interface with preserved surface superconductivity. Here, we report the preparation of the Josephson junction out of the stacked Bi 2 Sr 2 CaCu 2 O 8+d crystals using the cryogenic dry transfer technique and encapsulating the junction with an insulating layer, that protects the interface during the electrical contacts evaporation at the 1×10 -6 mbar base pressure. We find that the Josephson critical current $I$ c has a maximum at low twist angles, comparable to that of the bulk intrinsic Josephson junctions, and is reduced by two orders of magnitude at twist angles close to 45°. In conclusion, the reduction of $I$ c occurs due to a mismatch between superconducting $d$-wave order parameters, which suppresses the direct Cooper pair tunneling.

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2D materials75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYJosephson junctionsTwisted high temperature superconductorsVan der Waals heterostructures

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Martini, Mickey, Lee, Yejin, Confalone, Tommaso, Shokri, Sanaz, Saggau, Christian N., Wolf, Daniel, Gu, Genda, Watanabe, Kenji, Taniguchi, Takashi, Montemurro, Domenico, Vinokur, Valerii M., Nielsch, Kornelius, Poccia, Nicola. 2023-07-10. Twisted cuprate van der Waals heterostructures with controlled Josephson coupling. https://doi.org/10.1016/j.mattod.2023.06.007

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