Robust Electric-Field Input Circuits for Clocked Molecular Quantum-Dot Cellular Automata

Quantum-dot cellular automata (QCA) is a paradigm for low-power, general-purpose, classical computing designed to overcome the challenges facing CMOS in extreme limits of scaling. A molecular implementation QCA offers nanometer-scale devices with device densities and operating speeds which may surpass by several orders magnitude, all at room temperature. Here, proposal electric field bit write-in circuits extended clocked using $z$ component an applied field. Input electrodes, be much larger than cells themselves, apply input notation="LaTeX">$y$ component. The selects on field-sensitive portion circuit, shift register transmits downstream logic. circuit sensitive field, since even very weak drives as desired. also robust: coupling between segment fails strengths stronger those needed write bit. simple rotation eliminates this failure, under arbitrarily strong fields. modified tolerates significant unwanted notation="LaTeX">$x$ component, used neither clocking nor input. bits one road-block that must cleared order realize energy-efficient computation QCA. Write-in achieved simply relatively large electrodes respond tolerate fields without failing.