But there is at least an idea how to reduce the power consumption of semiconductor devices by a factor of 1 million.
The basic idea is to simply eliminate the flow of electrons, the ultimate source of power consumption. Researchers at the University of California at Berkeley said that magnetic processors could work without the need of electrons and function near the minimum power limit allowed by the second law of thermodynamics (Landauer limit). The project group estimates that a magnetic chip may only consume 18 millielectron volts of energy per operation at room temperature, which is about 1 million times below today's processors.
Instead of a traditional circuit, such magnetic processors could use nanometer-sized bar magnets for memory, logic and switching operations. "Today, computers run on electricity; by moving electrons around a circuit, you can process information," said Brian Lambson, a UC Berkeley graduate student in the Department of Electrical Engineering and Computer Sciences. "A magnetic computer, on the other hand, doesn't involve any moving electrons. You store and process information using magnets, and if you make these magnets really small, you can basically pack them very close together so that they interact with one another. This is how we are able to do computations, have memory and conduct all the functions of a computer."
While the goal is to create a computer that works at the Landauer limit, magnetic chips have substantial challenges - including the fact that they are not exactly small. The nanomagnets the Berkeley team is currently using to build magnetic memory are about 100 nanometers wide and about 200 nanometers long. They enable simple logic operations, but they are more than 10 times the size of traditional chip structures that are in development now. Lambson also noted that the magnets can be used as memory, but "the real challenge is getting the wires and transistors working." The magnets are also vulnerable to random "fluctuations from thermal effects, stray electromagnetic fields and other kinds of noise."
Needless to say, this technology is far from being mature. But hey, we can dream, right?
