Modern processors have struggled to push switching below one nanosecond because energy consumption, and with it heat, rises steeply at speed. Researchers at the University of Tokyo's Graduate School of Science, with collaborators including RIKEN and the Institute for Solid State Physics, have demonstrated a non-volatile device that changes its magnetic state in about 40 picoseconds, roughly a thousand times faster than nanosecond-class switching, while consuming very little energy.
The device is built from manganese-tin (Mn3Sn), an antiferromagnet whose binary magnetic state is rewritten by an extremely short electrical pulse. Switching relies on spin-orbit torque, a transfer of angular momentum that does not depend on heating; competing picosecond mechanisms reportedly drive temperature rises of several hundred degrees Celsius, degrading durability. The team also demonstrated writing with 60-picosecond photocurrent pulses generated by a telecom-band laser, a basic form of spintronic photoelectric conversion in which optical signals write directly to non-volatile memory.
Published in Science, the work sketches a route to computing and data-centre hardware that is simultaneously faster and dramatically cooler, with non-volatile memory that retains data without power yet keeps pace with logic. The photocurrent demonstration points further still, towards memory that interfaces natively with optical communications, letting signals arriving over fibre be written into storage directly without the energy-hungry conversions that constrain today's infrastructure.