Fault tolerance properties in quantum-dot cellular automata devices

We present a study of the joint influence of temperature and fabrication defects on the operation of quantum-dot cellular automata (QCA) devices. Canonical ensemble, a Hubbard-type Hamiltonian and the inter-cellular Hartree approximation were used, and a statistical model has been introduced to simulate defects in the QCA devices. Parameters such as success rate and breakdown displacement factor (BDF) were defined and calculated numerically. Results show the thermal dependence of BDF values of the QCA devices. The BDF values decrease with temperature. The joint influence of randomly missing dots and temperature was also studied.