CONTROL OF MAGNETIC-FLUX IN A YBA2CU3O7-DELTA THIN-FILM LOOP USING FEMTOSECOND LASER-PULSES

A superconducting optical flux-trap memory with a femtosecond pulsed l aser is proposed and then demonstrated, The magnetic flux is capped in a simple YBa2Cu3O7-delta thin film loop with a polarity controlled by means of optical supercurrent modulation. After removing the external bias current, the trapped fluxes are detected by observing electromag netic pulse radiation 60 cm away from the sample, which is excited by modulating a persistent current that circulates in the loop. The mecha nism for the readin of the magnetic fluxes is discussed in relation to the current distribution in the memory. (C) 1997 American Institute o f Physics.