The Future of Memory
by Tim Moran
Memory, from the very beginning of the data-processing age, has been crucial to the fast and accurate running of all types of computers.
"The History of Computer Memory" on About.com tells us the one of the very early forms of memory was "drum memory, [which] actually did use a drum as a working part." Data was loaded on to the drum, which was a metal cylinder coated with recordable ferromagnetic material. Next came magnetic core memory, in which "ceramic rings, called cores, stored information using the polarity of a magnetic field." Eventually we were blessed with semiconductor memory based on the integrated circuit. Commonly called RAM, this is the type of memory we are still using today, in one form or another (DRAM, SRAM, etc.).
Researchers at the Australian National University (ANU) have developed "the most efficient quantum memory for light in the world, taking us closer to a future of super-fast computers and communication secured by the laws of physics." A recent story on the ANU news site, "World First for Quantum Memory Storage," reports that the "team at the ANU Research School of Physics and Engineering used a technique they pioneered to stop and control light from a laser, manipulating electrons in a crystal cooled to a chilly -270 degrees Celsius. The unprecedented efficiency and accuracy of the system allows the delicate quantum nature of the light to be stored, manipulated, and recalled."
Are you with me here? Not sure I am either, but, this is how the process is explained by Morgan Hedges, the lead researcher: "Light entering the crystal is slowed all the way to a stop, where it remains until we let it go again. When we do let it go, we get out essentially everything that went in as a three-dimensional hologram, accurate right down to the last photon."
So how does this translate into memory? Well, for one thing, the inherent uncertainty of quantum mechanics assures that some of the information in the light will be lost "the moment its measured," which renders the hologram read-once. That quantum mechanics guarantees that the information can be read only once would make this technology--should it ever be commercialized--"perfect for secure communications."
In addition to possibly enabling quantum computing that would be "times faster and more powerful than contemporary computing," the researchers anticipate that light storage "will allow tests of fundamental physics, such as how the bizarre phenomenon of quantum entanglement interacts with of the theory of relativity." This mind-bending notion suggests that two crystals could be entangled and the reading of one memory would simultaneously alter whatever is stored in the other crystal, no matter the location of either nor their distance apart. I suggest you read the article should you want to understand more about this quantum craziness--or see if you can get through to Stephen Hawking and ask him.
Me, I'm hopelessly entangled.