A team of scientists has created racetrack memory, a new type of enhanced digital data storage. Racetrack memory, which reconfigures magnetic fields, could supplant current methods of mass data storage, such as flash memory and disk drives, due to its improved density of information storage, faster operation, and lower energy use. The team’s focus was on a skyrmion racetrack memory — an undeveloped type of memory that reverses the processes of existing storage.
Today’s devices, from smartphones to laptops to cloud-based storage, rely on a growing density of digital data storage. Because the need will only increase in the future, researchers have been seeking ways to improve storage technologies — enhancing their capacities and speed while diminishing their size.
Many current mass data storage platforms function like an old musical cassette tape, which reads data by moving material (i.e., the tape) with a motor across a reader (i.e., in the cassette player), then decodes the information written on the material to reproduce sound. By contrast, racetrack memory does the opposite: the material stays in place and the information itself is moved across the reader without the need to move mechanical parts such as a motor.
The information is carried by a magnetic object called a skyrmion that can be moved by applying an external stimulus such as a current pulse. A skyrmion, a magnetic texture with a whirling spin configuration, spins as if curled up in a ball. This ball of spins represents a bit of information that can be moved quickly as well as created and erased with electrical pulses. Skyrmions can be very small and moved at high speed at a low energy cost, thus enabling faster, high-density, and more energy-efficient data storage.
Small skyrmions, however, are only stable in very specific material environments, so identifying the ideal materials that can host skyrmions and the circumstances under which they are created is a first priority for making the technology applicable. The researchers’ tests indicated that magnetic materials that generate only small magnetic fields — materials known as ferrimagnets — are favorable for creating small skyrmions and moving them. They showed that magnetic interactions can be precisely controlled in these materials to favor the formation of skyrmions.