Single-electron pass-transistor logic and its application to a binary adder

A new type of logic for constructing single-electron transistor (SET) circuits is proposed. The logic uses multigate SETs as pass transistors. The pass signals are routed with a small voltage so that the SETs can utilize Coulomb blockade effects. They are boosted at the output node when transferred to the input gates of other circuits. Since the multigate configuration enables us to implement XOR function using just one device, the logic can express sum- and carry-bits of an adder in a compact way. We have fabricated an elemental circuit of the logic and tested the basic operation of the SETs in the circuit. We also describe a multibit binary adder based on the logic, and discuss the circuit size and speed.