The Academy of Finland has granted €1.6 million to a consortium based at Tampere University of Technology (TUT) under the "Programmable Materials" funding scheme. The project runs from 1 September 2012 to 31 August 2016 and is entitled "Photonically Addressed Zero Current Logic through Nano-Assembly of Functionalised Nanoparticles to Quantum Dot Cellular Automata" ( PhotonicQCA).
PhotonicQCA fits well to the objectives of the Programmable Materials scheme of Academy of Finland, which looks for visionary new ways to use materials. The project combines expertise to look at the unique possibilities of combining organic chemistry, semiconductor growth and nanofabrication to put the basis of a visionary technology platform for future nanoelectronic devices and logic circuits.
The key idea behind the project is the so-called quantum dot cellular automaton (QCA). In QCAs, pieces of semiconductor so small that single electronic charges can be measured and manipulated are arranged into domino like cells. Like dominos, these cells can be arranged so that the position of the charges in one cell affects the position of the charges in the next cell, which allows making logical circuits out of these "quantum dominos". But, no charge flows from one cell to the next, i.e. no current. This, plus the extremely small size of QCAs, means that they could be used to make electronic circuits at densities and speeds not possible now. However, realisation of the dots and cells and making electrical connections to them has been a huge challenge.
Professors Donald Lupo from Department of Electronics, Mircea Guina and Tapio Niemi from Optoelectronics Research Centre (ORC), and Nikolai Tkachenko and Helge Lemmetyinen from Department of Chemistry and Bioengineering, want to investigate a completely new approach. They want to attach tailor-made molecules, optical nanoantennas, to the quantum dots, which can inject a charge into a dot or enable charge transfer between the dots when light of the right wavelength shines on them. This concept will be combined with the expertise at TUT's Optoelectronics Research Centre concerning "site-specific epitaxy", i.e. growing the quantum dots in the right place using nanofabrication techniques, which would enable a solid-state technology platform compatible with standard electronic circuits. If this works, then someday QCAs could be written and read with light.
Project coordinator, Professor Donald Lupo says: "As far as we can tell, no one has ever tried anything like this before. It's a completely new idea. It's highly risky because of many technological challenges, but the potential is amazing; being able to get rid of electrical connections and write and read nanoelectronic circuits using only light would be a huge breakthrough".
Further information:
Tampere University of Technology, Finland (www.tut.fi)
Professor Donald Lupo, Department of Electronics
tel. +358 40 849 0614, donald.lupo@tut.fi
Professor Mircea Guina, Optoelectronics Research Centre (ORC)
tel. +358 40 849 0004, mircea.guina@tut.fi
Professor Nikolai Tkachenko, Department of Chemistry and Bioengineering
tel. +358 40 748 4160, nikolai.tkachenko@tut.fi
The Academy of Finland, "Programmable Materials" funding scheme: http://www.aka.fi/en-GB/A/Programmes-and-Cooperation/Research-programmes/Ongoing/Programmable-materials/