The industry has spent decades searching for a kind of “universal memory” that could combine the speed of SRAM, the density of DRAM, the persistence of flash, and low power consumption. That challenge becomes even harder at ultrafast timescales, where many experimental switching technologies partially rely on brute-force heating to destabilize and flip states rapidly.

The faster the switching, the more severe the thermal problem often becomes. Several previously demonstrated picosecond-scale switching approaches cited in the paper involve temperature rises of several hundred Kelvin during operation.

The Tokyo researchers are instead pursuing a radically different switching mechanism through a field known as spintronics. Instead of storing information as an electrical charge, spintronic devices store information using magnetic states.