LOGIC DESIGN BASED ON NEGATIVE DIFFERENTIAL RESISTANCE CHARACTERISTICS OF QUANTUM ELECTRONIC DEVICES

New quantum electronic devices such as resonant tunnelling diodes and transistors have negative differential resistance characteristics that can be exploited to design novel high-speed circuits. The high intrin sic switching speed of these devices, combined with the novel circuit structures used to implement standard logic functions, leads to ultraf ast computing circuits. The new circuit structures presented here prov ide extremely compact implementations of functions such as carry gener ation and addition. The most significant impact of these circuits on t he field of logic design is the introduction of a totally new set of r elative costs of various basic gates; reevaluation of the logic in the light of these new cost functions leads to ultrafast and compact desi gns.