SQUID Device

Superconductor materials shows two unique properties: (i) flow of dissipation free current, and (ii) expulsion of magnetic field lines through the superconductor material in presence of magnetic field i.e. Meissner effect. In addition, the superconducting thin film is used to fabricate Josephson junction devices which are used in various applications such as radiation detector, Terahertz detector, microwave detector, SQUID devices etc. In this work, we have demonstrated the fabrication of step edge based YBCO Josephson junction and SQUID device. SQUID devices are most sensitive magnetometer which are used in scanning SQUID microscopes, magnetoencephalography etc.

Atomic force microscopy images of fabricated (a) step-edge, optical microscope images of fabricated (b) Josephson junction, and (c) SQUID device on STO substrate respectively, and current-voltage characteristics of fabricated (d) Josephson junction, (e) SQUID device on STO substrate respectively.