The Best of Both Worlds
For most office workers, booting up the computer is part of their morning ritual. Depending on the computer, it takes several minutes until the data is read from the hard drive into the working memory and the system is configured. This is necessary because while the working memory can quickly supply the data for ongoing processing in a matter of milliseconds, it requires non-stop electric power supply while it is up and running. And while the data are safely stored on the hard drive even if there is a power failure, the down side is relatively long read and write times. The ideal solution would involve a kind of storage that combines the advantages of both types. At Jülich, research to find this solution is under way.
Completely new architectures for chips are being developed that operate without transistors like the working memory and without magnetic cylinders like the hard drives. So-called resistive storage uses materials whose electrical resistance can be changed locally with little effort. When fine electrodes are used to create voltage in samples of strontium titanate or titanium dioxide, oxygen ions move back and forth in the material and form a conduction channel between the electrodes. The channel typically has a diameter between 5 and 50 nanometres and thus reduces the space requirements by a factor of 1000 compared to today’s conventional storage elements.
In addition, the information can be read just as quickly as in today's working memory. Yet the channels and in turn, the stored information, are also retained when the power is turned off and the data are available in the long term, just like on a hard drive. Only when a countervoltage is applied does the channel return to its original low resistance values and the data are overwritten.
Researchers at Jülich are still testing their prototypes in the clean room lab and need to analyse a number of details of the innovative materials under the high-performance microscope. But the cooperating businesses are already signalling a great deal of interest today and so chances are good that "Jülich inside" will also apply to the computers of tomorrow.