[19p-E302-1~8] 先端イオン顕微鏡技術って何？ナノスケール材料・デバイスへの展開

▲ [19p-E302-4] YBaCuO Nano-SQUIDs Fabricated by Focused Helium Ion Beam Direct Writing

〇Shane Cybart¹、Hao Li¹、Ethan Cho¹ (1.Univ. of California Riverside)

キーワード：superconductor, helium ion micrscope, squid

We successfully fabricated high-transition temperature (high-\textit{T}$_C$) nano-scale superconducting quantum interference devices (nano-SQUIDs) by using a 32-keV focused helium ion beam (FHIB). The $\sim$0.5 nm beam of the FHIB was used to disorder the crystaline lattice of YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) causing disorder that converts the material from superconductor to insulator at high dose. The SQUID loop size was 400 nm $\times$ 400~nm, with 200-nm wide Josephson junctions. Devices operated over a wide range of temperatures from 50 to 4~K and exhibited large voltage modulation with magnetic field as high as 500~$\mu$V.