HELICAL LOGIC

Helical logic is a theoretical proposal for a future computing technol ogy using the presence or absence of individual electrons (or holes) t o encode is and Os. The electrons are constrained to move along helica l paths, driven by a rotating electric field in which the entire circu it is immersed. The electric field remains roughly orthogonal to the m ajor axis of the helix and confines each charge carrier to a fraction of a turn of a single helical loop, moving it like water in an Archime dean screw. Each loop could in principle hold an independent carrier, permitting high information density. One computationally universal log ic operation involves two helices, one of which splits into two 'desce ndant' helices. At the point of divergence, differences in the electro static potential resulting from the presence or absence of a carrier i n the adjacent helix controls the direction taken by a carrier in the splitting helix. The reverse of this sequence can be used to merge two initially distinct helical paths into a single outgoing helical path without forcing a dissipative transition. Because these operations are both logically and thermodynamically reversible, energy dissipation c an be reduced to extremely low levels. This is the first proposal know n to the authors that combines thermodynamic reversibility with the us e of single charge carriers. It is important to note that this proposa l permits a single electron to switch another single electron, and doe s not require that many electrons be used to switch one electron. The energy dissipated per logic operation can very likely be reduced to le ss than 10(-27) J at a temperature of 1 K and a speed of 10 GHz, thoug h further analysis is required to confirm this. Irreversible operation s, when required, can be easily implemented and should have a dissipat ion approaching the fundamental limit of In 2kT.