High-Speed Optical Switching of Magnetic Memory Achieved
Magnetic memory devices have been used in computers for a long time, but have been receiving some stiff competition lately from solid state memories. Part of why SSDs are able to compete with magnetic HDDs is that they are typically faster and use less power. Researchers at Ames Laboratory, Iowa State University, and the University of Crete however have made a discovery which may help give the edge back to magnetic memories.
Magnetic memory works by flipping the direction of a magnetic field, and researchers have been searching for ways to make this flipping faster and more efficient, such as heating the material. One promising group of materials for this is colossal magnetoresistive (CMR) family of materials, as they react well to external magnetic fields, such as those used for writing information, but do not require much heating. These materials are not well understood though, which is where these researchers come in as they used ultra-fast laser pulses to trigger the flipping of magnetic fields. For one of these materials, the researchers discovered they were able to flip the fields within a 100 femtosecond pulse, which means it may be possible to create terahertz speed hard drives and magnetic RAM.
While that speed is certainly impressive, it means more than just fast memory. As this was an all-optical process and occurred so quickly, the physics involved must be quantum mechanical in nature. Potentially this knowledge could lead to CMR-based magnetic memories operating at their maximum possible speed.
Source: Ames Laboratory