|Memory Design Can Lead to Faster Computers
Imagine a computer that doesn’t lose data even in a sudden power outage, or a coin-sized hard drive that could store 100 or more movies.
Magnetic random-access memory, or MRAM, could make these possible, and would also offer numerous other advantages. It would, for instance, operate at much faster than the speed of ordinary memory but consume 99 percent less energy.
The current challenge, however, is the design of a fast, reliable, and inexpensive way to build stable and densely packed magnetic memory cells.
A team of researchers led by Chia-Ling Chien, a professor of physics and astronomy, writing in a recent issue of Physical Review Letters, has come up with one possible answer: tiny, irregularly shaped cobalt or nickel rings that can serve as memory cells. These “nanorings” can store a great quantity of information. They also are immune to the problem of “stray” magnetic fields, which “leak” from other kinds of magnets and can thus interfere with magnets next to them.
The team’s asymmetrical design allows more of the nanorings to end up in a so-called “vortex state,” meaning they have no stray field at all. With no stray field to contend with, the nanorings act like quiet neighbors who don’t bother each other, and thus can be packed extremely densely. As a result, the amount of information that can be stored in a given area is greatly increased.