A uhf superconducting magnetometer utilizing a new thin film sensor

Abstract

A new type of thin film superconducting quantum interference device is described. It has many advantages compared to usual ones: higher critical temperature, readily established critical current (any value can be chosen between 0.5 μA and 1.5 μA with a ±0.1 μA accuracy), high reliability, and low cost. This SQUID works with a uhf magnetometer utilizing a 350 MHz pumping frequency. All rf circuits are perfectly matched, and the use of a particular rf detection leads to an improved signal-to-noise ratio. A sensitivity of 2×10−4 φ0/√Hz is easily obtained, with a slew rate of 2500 φ0/sec.