Single-Event Upset in Molecular Quantum Cellular Automata

Molecular quantum cellular automata (QCA) provides a paradigm for molecular electronics in which the configuration of charges at reduction-oxidation centers of molecules encodes binary information, and the electrostatic forces enable performing logic operations at the molecular scale. Cosmic rays or impurities in packaging materials can cause electric charges to tunnel into a QCA cell, leading to single-event upset (SEU). The effect of SUE on the functionality of a majority gate comprised of a QCA cell, in which two cationic molecular dimers interact through intermolecular Coulomb forces, is analyzed using the Hubbard model and full quantum chemical calculations. For this purpose, we introduce a complementary input model within a minimal framework for the molecular QCA majority gate. The response function of a single-input QCA cell and the polarization table of a three-input majority gate are evaluated in normal and SEU operation modes using the complementary input model in conjunction with the Hubbard model and quantum chemical calculations. The ab initio results indicate the possibility of designing SEU fault-tolerant QCA devices.