Performances of high Tc dc SQUID utilizing bicrystal junctions with 30° misorientation angle have been studied. Junction resistance R,=10 Q and critical current /=10-20 uA can be obtained rather easily at 7=77 K with this technology. As a result, voltage modulation depth as high as 50 |iV, and flux noise as low as 5 /Hz2 are obtained for the lOOpH-SQUlD. The measured values of the voltage modulation depth agree reasonably well with the numerical simulation, while the measured values of the flux noise are about 2 or 3 times larger than the simulation. The reason for the high noise level is discussed by taking into account imperfection of junctions.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering