Josephson junctions and SQUIDs created by focused helium ion beam irradiation of YBa${}_2$Cu${}_3$O${}_7$

B. Müller, M. Karrer, F. Limberger +6

By scanning with a $30\mathrm{keV}$ focused He ion beam (He-FIB) across YBa${}_2$Cu${}_3$O${}_7$ (YBCO) thin film microbridges, we create Josephson barriers with critical current dens…