Superconducting Quantum Interference in Twisted van der Waals Heterostructures

Abstract

Modern Superconducting QUantum Interference Devices (SQUIDs) are commonly fabricated from either Al or Nb electrodes, with an in-situ oxidation process to create a weak link between them. However, common problems of such planar nano- and micro-SQUIDs are hysteretic current-voltage curves, and a shallow flux modulation depth. Here, we demonstrate the formation of both Josephson junctions and SQUIDs using a dry transfer technique to stack and deterministically misalign flakes of NbSe${}_2$; allowing one to overcome these issues. The Josephson dynamics of the resulting twisted NbSe${}_2$-NbSe${}_2$ junctions are found to be sensitive to the misalignment angle of the crystallographic axes. A single lithographic process was then implemented to shape the Josephson junction into a SQUID geometry with typical loop areas of $\simeq$ 25 $\mu m^2$ and weak links $\simeq$ 600 nm wide. These devices display large stable current and voltage modulation depths of up to $\Delta I_c\simeq$ 75$\%$ and $\Delta V\simeq$ 1.4 mV respectively.

arXiv comment12 pages, 6 figures

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Cited by in corpus (11)

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• Persistent Josephson tunneling between Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+x}$ flakes twisted by 45${}^{\circ }$ across the superconducting dome
• Prominent Josephson tunneling between twisted single copper oxide planes of Bi${}_2$Sr${}_{2-x}$LaxCuO${}_{6+y}$
• Transport evidence of superlattice Dirac cones in graphene monolayer on twisted boron nitride substrate
• Josephson Effect in NbS${}_2$ van der Waals Junctions
• Pick-up and assembling of chemically sensitive van der Waals heterostructures using dry cryogenic exfoliation
• Moiré Superstructures in Marginally-Twisted NbSe${}_2$ Bilayers
• Twisted Nodal Superconductors
• Transient vortex dynamics and evolution of Bose metal from a 2D superconductor on MoS${}_2$
• Flux pinning in superconducting multilayer 2H-NbSe${}_2$ nano-step junction