Building Blocks for Fluctuation Based Calculation in Single Electron Tunneling Technology

Fluctuations and noise are important factors interfering with the operation of devices and circuits, and this effect will become stronger as feature sizes decrease. This paper presents two building blocks for single electron tunneling (SET) circuits that are designed with signal fluctuations in mind. One of these blocks, a so-called Hub, outputs its signals to other building blocks by repeatedly offering its signals at its output terminals, and taking them back when they cannot be delivered. Based on a random scheme of signaling, the Hub requires fluctuations to drive its operation. The other building block, a Conservative Join, is designed to work in cooperation with the Hub, though it does not require fluctuations. We propose SET circuit topologies for both blocks, and analyze their behavior at a temperature of IK by computer simulations with SIMON 2.0. The two very different modes of operation in the blocks-fluctuation vs. non-fluctuating-can be accommodated by appropriately tuning circuit parameters, as we show. Utilizing these proposed topologies we then present an example of a network constructed using the two building blocks.