Modeling and Evaluating Errors Due to Random Clock Shifts in Quantum-Dot Cellular Automata Circuits

A Defects Simulator for Robustness Analysis of QCA Circuits

“…To date, the majority of the automatized methods for QCA errors analysis [16] [37] [18] are not flexible enough to deal with the simultaneous insertion of defects of multiple classes into the cells within a structure. Moreover, other current error analysis approaches usually use fixed parameters for the defects levels, as the displacement/ misalignment shifts, rotation angles and the number of extra/ missing dots in a cell [38] [10] and [39].…”

“…Besides the defective cells, the behavior of a QCA system may be substantially affected due to deviations in the clock signals [18] [35]. As previous exposed in the Section II, the clock signals are provided by an external circuit, which is also subjected to defects and unusual operation conditions, such as temperature effects.…”

“…The standard deviations in the clock signals phases are likely to cause errors in the output signals of the QCA circuits, since they potentially affect the correct information sequencing. Such errors may manifest themselves in one of two possible ways, which are unwanted delays or inversions at the primary outputs [18]. The unwanted delay error occurs because the clocking zone attributed to the output cell latches out of sequence, so the information is propagated forward either sooner or later than expected.…”

“…Another challenge of QCA technology is its susceptibility to errors that may occur due to defective cells, caused by variations in the manufacturing process [10]. Consequently, several works focus on the creation of robust QCA structures [11] [12] [13] [14] as well as methodologies for error analysis in QCA circuits [15] [16] [17] [18]. In order to enable evaluation of circuit robustness and verification of reliability enhancing techniques, this work presents a QCA Defects Simulator based on a novel methodology for error exploration.…”

A comparative analysis and design of quantum‐dot cellular automata memory cell architecture

“…Generally speaking, noises in the QCA circuit refer to sneak noise and random charge. Sneak noise is created due to clocking phase shift [27] and lack of clocking symmetry. In this design, sneak noise problem has been solved by arranging the QCA cells and clock zones in such a regular and symmetrical way (see Figure 6), that unwanted signal coupling is diminished, hence sneak noise has not been highlighted here.…”