ABRIKOSOV VORTEX MEMORY BASED ON A SINGLE VORTEX

An Abrikosov vortex memory device based on a cross strip superconducting-normal-insulating-superconducting (SNIS) Josephson junction has been developed to investigate the feasibility of using the motion of a single vortex to store information and perform logic. The write operation is performed by moving a single vortex from one pinning site to another using a current in one leg of the cross strip junction. The read operation is performed by measuring the Josephson voltage at a fixed bias Josephson current. For these PbBi-Al2O3-Al-Pb SINS junctions, the Josephson voltage depends on the vortex position because the vortex distorts the Fraunhofer diffraction pattern in a predictable way. The device is superior to earlier superconductor-normal-superconductor (SNS) devices in that the junction voltages are millivolts and can be read with rather simple electronics.