As far as the speed of computers is concerned, conventional technologies are reaching their limits. New technologies are therefore needed if computers are to become even faster in the future. Researchers at the Institute of Physics at the Johannes Gutenberg University in Mainz (JGU) have now made a discovery that lays a possible foundation for such new technologies - such as the virtually currentless computer.
The background: electrons rotate around their own axis, a phenomenon known as spin. It is used, for example, in hard disks to store information - so spin is a mandatory prerequisite for today's electronics. Molecular electronics in turn is a further development of microelectronics, in which individual molecules form the components. For example, polymers, i.e. long molecular chains, can be used for this purpose. "Small changes in the structure of these polymers can be implemented much more easily and precisely than corresponding changes in traditional semiconductor materials," explains Dr. Erik R. McNellis, group leader at the Institute of Physics at JGU. The polymers can be designed atom by atom. What has not yet been clear, however, is how the spins move in these materials.
"Until now, it was assumed that the spins move with the electrons - i.e. are coupled to the charge transport, i.e. the current," says McNellis. "We were now able to refute this assumption: The spins by no means just travel with the electrons, but jump from one polymer chain to the next, mainly due to vibrations. This opens up a whole new dimension in technology." These vibrations can be influenced by the design of the molecules, the device geometry and the control of the temperature. During the investigation, McNellis and his team carried out the simulations for the experiments carried out at Cambridge University.