Intramolecular Hamiltonian logic gates

An intramolecular computing model is presented that is based on the quantum time evolution of a single molecule driven by the preparation of a non-stationary single-electron state. In our scheme, the input bits are encoded into the coupling constants of the Hamiltonian that governs the molecular quantum dynamics. The results of the computation are obtained by carrying out a quantum measurement on the molecule. We design reliable AND, XOR, and HALF-ADDER logic gates. This opens new avenues for the design of more complex logic circuits at a single-molecular scale. (C) 2004 Elsevier B.V. All rights reserved.