Long-time stable and high-performance YBa2Cu3O7 nanoSQUIDs with more interfaces

Autor: Jianxin Lin, Deheng Zhang, Lianjun Zhao, Zejun Shi, Qimin Wang, Shenghao Qin
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: AIP Advances, Vol 12, Iss 4, Pp 045101-045101-7 (2022)
Druh dokumentu: article
ISSN: 2158-3226
DOI: 10.1063/5.0086252
Popis: We report on the fabrication and characterization of nanopatterned superconducting quantum interference devices (SQUIDs) based on grain boundary Josephson junctions in epitaxially grown multilayer YBa2Cu3O7 (YBCO)/SiTrO3 (STO) thin films. Nanopatterning is performed by Ga+ focused ion beam milling. The evolution of the electric transport and noise properties of the YBCO nanoSQUIDs over a time span of more than one year are recorded and analyzed. We find that the multilayer YBCO/STO nanoSQUIDs show stable and high performance over time. The critical current decreases within ∼40 days by 30%–50% and then remains almost constant without obvious decline trend for nanoSQUIDs with STO layer as the interface even more than 380 days, which demonstrates the superiority of STO as the capping layer. Moreover, we find that the multilayer nanoSQUIDs have about an order of magnitude smaller low-frequency excess flux noise (compared to similar single layer devices) with root-mean-square spectral density ∼5–6 µΦ0/Hz1/2 at 1 Hz. For one device, we show that the low-frequency excess noise does not degrade within three months.
Databáze: Directory of Open Access Journals