4 logic states using 2 resonant tunnelling diodes

Using a series connection of two specially designed resonant tunnelling diodes, we observed three negative differential resistance regions, resulting in four possible logic states. This behaviour can be expanded, at least in theory, to n tunnelling diodes, resulting in 2π - 1 times switching and 2π logic states. These new devices can be used for analogue/digital conversion and multivalued logic or as multistate memory cells using only a minimum in device area. © 1989, The Institution of Electrical Engineers. All rights reserved.status: publishe