By Gary Thomas
A consortium based in Tampere University of Technology (TUT) has received €1.6 million grant from the Academy of Finland under its ‘Programmable Materials’ funding scheme.
The project titled ‘Photonically Addressed Zero Current Logic through Nano-Assembly of Functionalised Nanoparticles to Quantum Dot Cellular Automata" ( PhotonicQCA)’ takes place from September 1, 2012 through August 31, 2016.
PhotonicQCA has the technological know-how to explore the possibilities of integrating nanofabrication, semiconductor growth and organic chemistry to lay the cornerstone of a farsighted technology platform to develop future nanoelectronic logic circuits and devices.
The project’s key concept is the quantum dot cellular automaton (QCA) wherein tiny semiconductor pieces that allow the measurement and control of single electronic charges are aligned into domino like cells. This specific arrangement enables the position of the charges in a cell to impact the position of the next cell’s charges, thus creating logical circuits from these ‘quantum dominos,’ but without any current flow between the cells. This feature together with QCAs’ ultra-small size makes them useful in the development of electronic circuits with unprecedented densities and speeds.
Nevertheless, the major challenge is the development of the dots and cells and establishing electrical connections between them. Professors Helge Lemmetyinen and Nikolai Tkachenko from Department of Chemistry and Bioengineering together with Tapio Niemi and Mircea Guina from Optoelectronics Research Centre, and Donald Lupo from Department of Electronics seek an entirely new technique.
Their concept involves the attachment of optical nanoantennas to the quantum dots that enable the injection of a charge into dot or transfer of charges between the dots when they are illuminated by light with the right wavelength. This idea will be integrated with technological know-how at TUT's Optoelectronics Research Centre regarding ‘site-specific epitaxy,’ wherein nanofabrication techniques are used to grow quantum dots in the designated place. This combination may result in the development of a solid-state technology platform that is compatible with typical electronic circuits. If it is successful, it may be possible to write and read QCAs with light someday.
According to Professor Donald Lupo, Project coordinator, it is an innovative concept because reading and writing nanoelectronic circuits with only light is a major breakthrough.