Quantum-Dot Cellular Automata: Logic Without Current

This simulator models quantum-dot cellular automata (QCA), a nanoscale computing architecture that encodes a bit not as current flow but as the electrostatic polarization of a 4-dot cell shared by two electrons. Flip a driver cell and watch each neighbor re-settle into the Coulomb-energy-minimizing polarization in turn, cascading a logic signal down a wire with zero charge transport. Switch to the majority-gate mode to see three inputs vote on a shared device cell — the universal QCA primitive — and lock one input to turn it into an AND or OR gate.