Anisotropic effect of the magnetic sensor formed from metal/high Tc superconductor contact

The magnetic sensor formed via a metal/high-T_c superconductor small contact shows anisotropic properties below the lower critical field (H_cl). An Ag wire was connected directly to the superconductor by an ultrasonic bonding method. It is shown that the resistance was changed by the field parallel to the superconductor surface, while it was not affected by the vertical field. The change is estimated to be 5×10^-5 Ω/G. No hysteresis is observed. Magnetic field direction can be detected by using these properties and a deferential measuring method of the resistance