Advanced quantum device technology
The QUDOS project focused on the development of a robust negative-differential resistance (NDR) device technology available on a silicon substrate. The innovative technology was extensively elaborated in terms of manufacturability, compatibility to silicon circuitry, and performance of emerging candidates such as resonant tunnelling devices. Resonant tunnelling devices constitute one of the key types of quantum-effect devices as they show several advantages. They operate normally under room temperatures and, with the aid of an integration process, they offer a large variety of options in design. Such devices are resonant tunnelling diodes (RTDs) and can be designed on the basis of threshold logic computational models. RTDs are built of threshold gates instead of the commonly used Boolean gates such as AND, OR and similar. Although they can be realised very efficiently, they are able to complete more complicated functions. The project work focused on developing a new computational model - the multi-threshold threshold gates (MTTGs) that can further increase the functionalities of conventional threshold gates. The developed MTTG circuit topology is highly suitable for implementation with mobile RTD structures. It was shown that suitable sizing of RTDs can result in two-output neurons. Furthermore, the circuit topology was also extended to implement programmable neurons and the methodology was exploited to make the design of complex neurons with RTDs more systematic. The MTTG circuit approach has been proven useful allowing the implementation of nano-pipelining at the gate level. For further information on the project click at: http://www.hlt.uni-duisburg.de/research/projekt_dokumente/qudos/qudos1.html