Characterization of intrinsic Josephson junction stack using high-T_c superconducting Bi_2Sr_2CaCu_2O_(8+δ)

摘要

We are reporting stack fabrication to study interlayer characteristics in high temperature superconductor single crystal whisker through focused ion beam (FIB). We fabricate a stack area of 2 pm x 2 p.m and height of approximately 300 nm using FIB etching, which have several hundred of elementary Josephson junctions in c-axis. This stack has fabricated by rotation and tilt of sample stage in FIB. We perform resistance (R) — temperature (T) characteristics in c-axis as well as in ab-plane and found transition temperature (T_c) of 77 K, which indicates good quality of Bi-2212 single crystal whiskers. We also measure current (I) — voltage (V) characteristics, which gives a well defined voltage gap (V_g≈2.4 V).