Full text loading...
Experimental setup for Josephson device annealing based on an argon laser source . The sample is mounted on the actuator with steps in order to align exactly the chosen area in the light focus. The heating of the sample is continuously monitored by an IR thermal camera.
Thermographic image of the chip temperature distribution during the laser beam action. It is evident in the possibility to perform a quite localized heating. The inset shows the time evolution of the sample temperature at the selected area (peak temperature).
Josephson junction current-voltage characteristics at before (open circles) and after (full circles) the laser annealing. For the sake of clarity the curves are mutually shifted. In the inset, the curve of the junction after the laser exposure is reported.
dc SQUID magnetometer flux-voltage characteristics measured at . The upper curve shows the behavior before the annealing process and the lower one is the characteristic of the same device after laser annealing.
Magnetic field noise spectral density of a dc SQUID magnetometer before the annealing process (upper curve) and after the laser exposure (lower curve) measured at . Due to the optimization of the critical current value by laser annealing, a reduction of more than one order of magnitude has been obtained.
Article metrics loading...