2021/01/12 by Liam S. Farrar, Aimee Nevill, Zhen Jieh Lim +3 · 1 citation
Physics and Astronomy · #cond-mat.supr-con #cond-mat.mes-hall
paper · pdf · doi:10.1021/acs.nanolett.1c00152
12 pages, 6 figures
arxiv created 2021/01/12 · arxiv updated 2021/08/18
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 NbSe2; allowing one to overcome these issues. The Josephson dynamics of the resulting twisted NbSe2-NbSe2 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 ≃ 25 μm2 and weak links ≃ 600 nm wide. These devices display large stable current and voltage modulation depths of up to ΔIc ≃ 75% and ΔV ≃ 1.4 mV respectively.