Newly observed phenomenon could impact processor design
02 April 2015
A new study of the movement of charges over interfaces of semiconductor materials could herald a new kind of logics operation in microelectronics.
The group of researchers, from Aalto University in Finland and the German University of Marburg, noticed a new kind of transport phenomenon for charges. In the phenomenon, a pair formed by a negative electron and a positive charge moves onto an interface, after which its 'message' is passed on to the other side of the interface, where it is carried on by a similar pair. The new theoretical result opens up interesting prospects for carrying out logic operations in electronics.
In addition to microelectronics, transport phenomena of charges are key to many biological processes, such as photosynthesis, explains Professor Ilkka Tittonen from Aalto University.
In the tunnelling phenomenon a particle can, with certain likelihood, penetrate the thin interface between materials, even if this is considered impossible according to classical physics. The newly discovered phenomenon is not based on the tunnelling of individual charges, but rather on the dynamics of a pair made of an electron and a positive charge that is connected to it electrically. This bound pair composed of an electron and a positively charged hole is called an exciton.
An optical pulse (at terahertz frequencies) brings information - or the so-called correlation of the electron hole pair - from one side of the interface to the other, without any tunnelling of the exciton itself. No equivalent phenomenon has hitherto been observed in the field of modern physics, according to Professor Tittonen.
The phenomenon combines semiconductor and terahertz techniques and it allows a new kind of logics operation in microelectronics. The group believes that it will be possible, on the basis of the phenomenon, to design new kinds of processors which function partly through optics and partly through electricity.