Researchers at UC Berkeley and UC Riverside are paving a path toward ultrafast magnetic memory. Their work could usher in a new generation of high-performance, low-power computing processors with high-speed, on-chip, non-volatile memories. The breakthrough could eventually result in more energy-efficient computer memory and processing technologies.
Today’s magnetic random access memory (MRAM) is far slower than the much more widely used random access memory (RAM). However, MRAM is attractive because the technology saves energy: Data is retained even when memory and CPU are turned off. Therefore, developing a non-volatile memory that’s as fast as charge-based RAM could lead to dramatic performance improvement and greater energy efficiency of computing devices.
The researchers found a magnetic alloy made up of gadolinium and iron that could accomplish higher speeds by switching the direction of the magnetism with a series of 10 picosecond electrical pulses. The pulsing temporarily boosts the energy of the iron atom’s electrons, which causes the magnetism in the iron and gadolinium atoms to apply torque on each other. Ultimately the metal’s magnetic poles are reoriented. That’s a new way of using electrical currents to control magnets, according to the researchers.
In a different study, published in Applied Physics Letters, researchers further improved performance by stacking a single-element magnetic metal such as cobalt on top of the gadolinium-iron alloy, allowing for switching with a single laser pulse in only seven picoseconds. As a single pulse, it was also more energy-efficient. The result? A processor with high-speed, non-volatile memory right on the chip.