Fabrication of submicron La$_{2-x}$Sr$_{x}$CuO$_{4}$ intrinsic Josephson   junction stacks
  Intrinsic Josephson junction (IJJ) stacks of cuprate superconductors have potential to be implemented as intrinsic phase qubits working at relatively high temperatures. We report success in fabricating submicron La$_{2-x}$Sr$_{x}$CuO$_{4}$ (LSCO) IJJ stacks carved out of single crystals. We also show a new fabrication method in which argon ion etching is performed after focused ion beam etching. As a result, we obtained an LSCO IJJ stack in which resistive multi-branches appeared. It may be possible to control the number of stacked IJJs with an accuracy of a single IJJ by developing this method. 
Yuimaru Kubo, Yamaguchi Takahide, Takayoshi Tanaka, Shinya Ueda,   Satoshi Ishii, Shunsuke Tsuda, A. T. M. Nazmul Islam, Isa...
cond-mat.supr-con quant-ph