US Patent 11094359 High retention multi-level-series magnetic random-access memory

A magnetic memory pillar structure having a plurality of magnetic memory elements connected in series, wherein switching of individual memory elements in the pillar structure can be accomplished based on differing switching current values of the magnetic memory elements. Each of the plurality of memory elements advantageously have similar retention values in spite of the different switching current values (latency values) as a result of a precessional spin current injection structure provided in the memory element or memory elements having the lower switching current value.